Barak was a military general in the Book of Judges in the Bible.

Barak or Barack may also refer to:

In places:

• Barak, Iran, a village in South Khorasan Province, Iran
• Barak, Israel, a moshav in northern Israel
• Barak, Lublin Voivodeship, a village in eastern Poland
• Barak, Masovian Voivodeship, a village in east-central Poland
• Barak River, part of the Surma-Meghna River System in India and Bangladesh
  • Barak Valley, an Indian valley which the river flows through

In other uses:

• Barack (brandy), a Hungarian apricot brandy
• Mubarak (name) or Barak or Barack, an Arabic name
• Bosnian Coarse-Haired Hound or Barak, a dog breed
• Barak Armored Brigade, an Israeli brigade under the Northern Command
• Operation Barak, a 1948 Haganah military operation north of Gaza
• Barak (Guantanamo captive 856), an Afghan detainee at Guantanamo Bay
• Barak, a character in The Belgariad by David Eddings

People with the surname[link]

• Aharon Barak (born 1936), former President of the Supreme Court of Israel
• Daphne Barak, Israeli-American interviewer
• Ehud Barak (born 1942), Israeli former Prime Minister and current Minister of Defense
• Josef Barák (1833–1883), Czech politician, journalist, and poet
• Jindřich Barák, Czech ice hockey player
• William Barak (1824–1903), the last traditional elder of the Wurundjeri-willam clan in Australia
• Wolf Blitzer or Ze'ev Barak

People with the given name[link]

• Barak Badash (born 1982), Israeli football player
• Barak Bakhar (born 1979), Israeli football player
• Barak Epstein (born 1979), American film director
• Barak Longmate (1738-1793), English genealogist and engraver
• Barak Moshe (born 1991), Israeli football player
• Barack Obama (born 1961), 44th and current President of the United States
• Barack Obama, Sr. (1936–1982), Kenyan economist and President Barack Obama's father
• Barak Sopé (born 1955), Vanuatu politician
• Barak Yitzhaki (born 1984), Israeli football player

See also[link]

• Barakah, Arabic for "blessing"
• Barag (disambiguation)
• Baraq (disambiguation)
• Barrack (disambiguation)
• Baruch, a given name
• Buraq (disambiguation)
• Baraka (disambiguation)
• Baraki Barak, home of the Baraki/Ormuri of Kurdish descent in Afghanistan's Logar Province
• Barak 1, an Israeli naval point-defense missile system
• Barak 8, an Israeli naval area-defense missile system
• Zadik Barak Levin syndrome, a human congenital disorder
• Barakzai, a number of different tribes in Afghanistan and western Pakistan
• Nawa, Afghanistan or Barak Khel, a village in Afghanistan

This disambiguation page lists articles associated with the same title. If an internal link led you here, you may wish to change the link to point directly to the intended article.

For the forename of U.S. President Barack Obama, see Mubarak.

Barak (English pronunciation: /ˈbɛəræk/ or /ˈbɛərək/;^[1] Hebrew: בָּרָק‎‎, Tiberian: Bārāq, "Lightning; Shine", Greek: βαρακ),, Al-Burāq (Arabic: البُراق‎ al-Burāq "lightning") the son of Abinoam from Kedesh in Naphtali, was a military general in the Book of Judges in the Bible. He was the commander of the army of Deborah, the prophetess and heroine of the Hebrew Bible. Barak and Deborah are credited with defeating the Canaanite armies led by Sisera, who for twenty years had oppressed the Israelites.

The story of the defeat of the Canaanites under the prophetic leadership of Deborah and the military leadership of Barak, is related in prose (Judges chapter 4) and repeated in poetry (chapter 5, which is known as the Song of Deborah). Chapter 4 makes the chief enemy Jabin, king of Hazor (present Tell el-Qedah, about three miles southwest of Hula Basin), though a prominent part is played by his commander-in-chief, Sisera of Harosheth-ha-goiim (possibly Tell el-'Amr, approximately 12 miles (19 km) northwest of Megiddo).

Deborah said that Barak would win, but Sisera would be killed by a woman. In the battle at Mount Tabor, a cloudburst occurred, causing the river to flood, thus limiting the maneuverability of the Canaanite chariots. Sisera fled, seeking refuge in the tent of a Kenite woman, Jael. Jael gave Sisera a drink of milk and he fell asleep from weariness. Then she pounded a tent peg through his head. When Barak came along, she let him see Sisera dead in her tent. Later Israel slew King Jabin.

Jael shows the slain Sisera to Barak, by Albert Joseph Moore.

Grave near Tel Kadesh attributed to Barak or Deborah

References[link]

In computational linguistics, word-sense disambiguation (WSD) is an open problem of natural language processing, which governs the process of identifying which sense of a word (i.e. meaning) is used in a sentence, when the word has multiple meanings (polysemy). The solution to this problem impacts other computer-related writing, such as discourse, improving relevance of search engines, anaphora resolution, coherence, inference et cetera.

Research has progressed steadily to the point where WSD systems achieve sufficiently high levels of accuracy on a variety of word types and ambiguities. A rich variety of techniques have been researched, from dictionary-based methods that use the knowledge encoded in lexical resources, to supervised machine learning methods in which a classifier is trained for each distinct word on a corpus of manually sense-annotated examples, to completely unsupervised methods that cluster occurrences of words, thereby inducing word senses. Among these, supervised learning approaches have been the most successful algorithms to date.

Current accuracy is difficult to state without a host of caveats. In English, accuracy at the coarse-grained (homograph) level is routinely above 90%, with some methods on particular homographs achieving over 96%. On finer-grained sense distinctions, top accuracies from 59.1% to 69.0% have been reported in recent evaluation exercises (SemEval-2007, Senseval-2), where the baseline accuracy of the simplest possible algorithm of always choosing the most frequent sense was 51.4% and 57%, respectively.

About[link]

A disambiguation process requires two strict things: a dictionary to specify the senses which are to be disambiguated and a corpus of language data to be disambiguated (in some methods, a training corpus of language examples is also required). WSD task has two variants: "lexical sample" and "all words" task. The former comprises disambiguating the occurrences of a small sample of target words which were previously selected, while in the latter all the words in a piece of running text need to be disambiguated. The latter is deemed a more realistic form of evaluation, but the corpus is more expensive to produce because human annotators have to read the definitions for each word in the sequence every time they need to make a tagging judgement, rather than once for a block of instances for the same target word.

To give a hint how all this works, consider two examples of the distinct senses that exist for the (written) word "bass":

1. a type of fish
2. tones of low frequency

and the sentences:

1. I went fishing for some sea bass.
2. The bass line of the song is too weak.

To a human, it is obvious that the first sentence is using the word "bass (fish)", as in the former sense above and in the second sentence, the word "bass (instrument)" is being used as in the latter sense below. Developing algorithms to replicate this human ability can often be a difficult task, as is further exemplified by the implicit equivocation between "bass (sound)" and "bass" (musical instrument).

History[link]

WSD was first formulated as a distinct computational task during the early days of machine translation in the 1940s, making it one of the oldest problems in computational linguistics. Warren Weaver, in his famous 1949 memorandum on translation,^[1] first introduced the problem in a computational context. Early researchers understood the significance and difficulty of WSD well. In fact, Bar-Hillel (1960) used the above example to argue^[2] that WSD could not be solved by "electronic computer" because of the need in general to model all world knowledge.

In the 1970s, WSD was a subtask of semantic interpretation systems developed within the field of artificial intelligence, but since WSD systems were largely rule-based and hand-coded they were prone to a knowledge acquisition bottleneck.

By the 1980s large-scale lexical resources, such as the Oxford Advanced Learner's Dictionary of Current English (OALD), became available: hand-coding was replaced with knowledge automatically extracted from these resources, but disambiguation was still knowledge-based or dictionary-based.

In the 1990s, the statistical revolution swept through computational linguistics, and WSD became a paradigm problem on which to apply supervised machine learning techniques.

The 2000s saw supervised techniques reach a plateau in accuracy, and so attention has shifted to coarser-grained senses, domain adaptation, semi-supervised and unsupervised corpus-based systems, combinations of different methods, and the return of knowledge-based systems via graph-based methods. Still, supervised systems continue to perform best.

Difficulties[link]

Differences between dictionaries[link]

One problem with word sense disambiguation is deciding what the senses are. In cases like the word bass above, at least some senses are obviously different. In other cases, however, the different senses can be closely related (one meaning being a metaphorical or metonymic extension of another), and in such cases division of words into senses becomes much more difficult. Different dictionaries and thesauruses will provide different divisions of words into senses. One solution some researchers have used is to choose a particular dictionary, and just use its set of senses. Generally, however, research results using broad distinctions in senses have been much better than those using narrow ones.^[3][4] However, given the lack of a full-fledged coarse-grained sense inventory, most researchers continue to work on fine-grained WSD.

Most research in the field of WSD is performed by using WordNet as a reference sense inventory for English. WordNet is a computational lexicon that encodes concepts as synonym sets (e.g. the concept of car is encoded as { car, auto, automobile, machine, motorcar }). Other resources used for disambiguation purposes include Roget's Thesaurus^[5] and Wikipedia.^[6]

Part-of-speech tagging[link]

In any real test, part-of-speech tagging and sense tagging are very closely related with each potentially making constraints to the other. And the question whether these tasks should be kept together or decoupled is still not unanimously resolved, but recently scientists incline to test these things separately (e.g. in the Senseval/SemEval competitions parts of speech are provided as input for the text to disambiguate).

It is instructive to compare the word sense disambiguation problem with the problem of part-of-speech tagging. Both involve disambiguating or tagging with words, be it with senses or parts of speech. However, algorithms used for one do not tend to work well for the other, mainly because the part of speech of a word is primarily determined by the immediately adjacent one to three words, whereas the sense of a word may be determined by words further away. The success rate for part-of-speech tagging algorithms is at present much higher than that for WSD, state-of-the art being around 95% accuracy or better, as compared to less than 75% accuracy in word sense disambiguation with supervised learning. These figures are typical for English, and may be very different from those for other languages.

Inter-judge variance[link]

Another problem is inter-judge variance. WSD systems are normally tested by having their results on a task compared against those of a human. However, while it is relatively easy to assign parts of speech to text, training people to tag senses is far more difficult.^[7] While users can memorize all of the possible parts of speech a word can take, it is often impossible for individuals to memorize all of the senses a word can take. Moreover, humans do not agree on the task at hand – give a list of senses and sentences, and humans will not always agree on which word belongs in which sense.^[8]

Thus, a computer cannot be expected to give better performance on such a task than a human (indeed, since the human serves as the standard, the computer being better than the human is incoherent),^{[citation needed]} so the human performance serves as an upper bound. Human performance, however, is much better on coarse-grained than fine-grained distinctions, so this again is why research on coarse-grained distinctions^[9][10] has been put to test in recent WSD evaluation exercises.^[3][4]

Common sense[link]

Some AI researchers like Douglas Lenat argue that one cannot parse meanings from words without some form of common sense ontology. For example, comparing these two sentences:

• "Jill and Mary are sisters." – (they are sisters of each other).
• "Jill and Mary are mothers." – (each is independently a mother).

To properly identify senses of words one must know common sense facts.^[11] Moreover, sometimes the common sense is needed to disambiguate such words like pronouns in case of having anaphoras or cataphoras in the text.

Sense inventory and algorithms' task-dependency[link]

A task-independent sense inventory is not a coherent concept^[12]: each task requires its own division of word meaning into senses relevant to the task. For example, the ambiguity of 'mouse' (animal or device) is not relevant in English-French machine translation, but is relevant in information retrieval. The opposite is true of 'river', which requires a choice in French (fleuve 'flows into the sea', or rivière 'flows into a river').

Also, completely different algorithms might be required by different applications. In machine translation, the problem takes the form of target word selection. Here, the "senses" are words in the target language, which often correspond to significant meaning distinctions in the source language ("bank" could translate to the French "banque" -- that is, 'financial bank' or "rive" -- that is, 'edge of river'). In information retrieval, a sense inventory is not necessarily required, because it is enough to know that a word is used in the same sense in the query and a retrieved document; what sense that is, is unimportant.

Discreteness of senses[link]

Finally, the very notion of "word sense" is slippery and controversial. Most people can agree in distinctions at the coarse-grained homograph level (e.g., pen as writing instrument or enclosure), but go down one level to fine-grained polysemy, and disagreements arise. For example, in Senseval-2, which used fine-grained sense distinctions, human annotators agreed in only 85% of word occurrences.^[13] Word meaning is in principle infinitely variable and context sensitive. It does not divide up easily into distinct or discrete sub-meanings.^[14] Lexicographers frequently discover in corpora loose and overlapping word meanings, and standard or conventional meanings extended, modulated, and exploited in a bewildering variety of ways. The art of lexicography is to generalize from the corpus to definitions that evoke and explain the full range of meaning of a word, making it seem like words are well-behaved semantically. However, it is not at all clear if these same meaning distinctions are applicable in computational applications, as the decisions of lexicographers are usually driven by other considerations. Recently, a task – named lexical substitution – has been proposed as a possible solution to the sense discreteness problem.^[15] The task consists of providing a substitute for a word in context that preserves the meaning of the original word (potentially, substitutes can be chosen from the full lexicon of the target language, thus overcoming discreteness).

Approaches and methods[link]

As in all natural language processing, there are two main approaches to WSD – deep approaches and shallow approaches.

Deep approaches presume access to a comprehensive body of world knowledge. Knowledge, such as "you can go fishing for a type of fish, but not for low frequency sounds" and "songs have low frequency sounds as parts, but not types of fish", is then used to determine in which sense the word is used. These approaches are not very successful in practice, mainly because such a body of knowledge does not exist in a computer-readable format, outside of very limited domains.^[16] However, if such knowledge did exist, then deep approaches would be much more accurate than the shallow approaches.^{[citation needed]} Also, there is a long tradition in computational linguistics, of trying such approaches in terms of coded knowledge and in some cases, it is hard to say clearly whether the knowledge involved is linguistic or world knowledge. The first attempt was that by Margaret Masterman and her colleagues, at the Cambridge Language Research Unit in England, in the 1950s. This attempt used as data a punched-card version of Roget's Thesaurus and its numbered "heads", as an indicator of topics and looked for repetitions in text, using a set intersection algorithm. It was not very successful,^[17] but had strong relationships to later work, especially Yarowsky's machine learning optimisation of a thesaurus method in the 1990s.

Shallow approaches don't try to understand the text. They just consider the surrounding words, using information such as "if bass has words sea or fishing nearby, it probably is in the fish sense; if bass has the words music or song nearby, it is probably in the music sense." These rules can be automatically derived by the computer, using a training corpus of words tagged with their word senses. This approach, while theoretically not as powerful as deep approaches, gives superior results in practice, due to the computer's limited world knowledge. However, it can be confused by sentences like The dogs bark at the tree which contains the word bark near both tree and dogs.

There are four conventional approaches to WSD:

• Dictionary- and knowledge-based methods: These rely primarily on dictionaries, thesauri, and lexical knowledge bases, without using any corpus evidence.
• Supervised methods: These make use of sense-annotated corpora to train from.
• Semi-supervised or minimally supervised methods: These make use of a secondary source of knowledge such as a small annotated corpus as seed data in a bootstrapping process, or a word-aligned bilingual corpus.
• Unsupervised methods: These eschew (almost) completely external information and work directly from raw unannotated corpora. These methods are also known under the name of word sense discrimination.

Almost all these approaches normally work by defining a window of n content words around each word to be disambiguated in the corpus, and statistically analyzing those n surrounding words. Two shallow approaches used to train and then disambiguate are Naïve Bayes classifiers and decision trees. In recent research, kernel-based methods such as support vector machines have shown superior performance in supervised learning. Graph-based approaches have also gained much attention from the research community, and currently achieve performance close to the state of the art.

Dictionary- and knowledge-based methods[link]

The Lesk algorithm^[18] is the seminal dictionary-based method. It is based on the hypothesis that words used together in text are related to each other and that the relation can be observed in the definitions of the words and their senses. Two (or more) words are disambiguated by finding the pair of dictionary senses with the greatest word overlap in their dictionary definitions. For example, when disambiguating the words in "pine cone", the definitions of the appropriate senses both include the words evergreen and tree (at least in one dictionary).

An alternative to the use of the definitions is to consider general word-sense relatedness and to compute the semantic similarity of each pair of word senses based on a given lexical knowledge base such as WordNet. Graph-based methods reminiscent of spreading activation research of the early days of AI research have been applied with some success. More complex graph-based approaches have been shown to perform almost as well as supervised methods^[19] or even outperforming them on specific domains.^[3][20] Recently, it has been reported that simple graph connectivity measures, such as degree, perform state-of-the-art WSD in the presence of a sufficiently rich lexical knowledge base.^[21] Also, automatically transferring knowledge in the form of semantic relations from Wikipedia to WordNet has been shown to boost simple knowledge-based methods, enabling them to rival the best supervised systems and even outperform them in a domain-specific setting.^[22]

The use of selectional preferences (or selectional restrictions) is also useful, for example, knowing that one typically cooks food, one can disambiguate the word bass in "I am cooking basses" (i.e., it's not a musical instrument).

Supervised methods[link]

Supervised methods are based on the assumption that the context can provide enough evidence on its own to disambiguate words (hence, world knowledge and reasoning are deemed unnecessary). Probably every machine learning algorithm going has been applied to WSD, including associated techniques such as feature selection, parameter optimization, and ensemble learning. Support Vector Machines and memory-based learning have been shown to be the most successful approaches, to date, probably because they can cope with the high-dimensionality of the feature space. However, these supervised methods are subject to a new knowledge acquisition bottleneck since they rely on substantial amounts of manually sense-tagged corpora for training, which are laborious and expensive to create.

Semi-supervised methods[link]

Because of the lack of training data, many word sense disambiguation algorithms use semi-supervised learning, which allows both labeled and unlabeled data. The Yarowsky algorithm was an early example of such an algorithm.^[23] It uses the ‘One sense per collocation’ and the ‘One sense per discourse’ properties of human languages for word sense disambiguation. From observation, words tend to exhibit only one sense in most given discourse and in a given collocation.

The bootstrapping approach starts from a small amount of seed data for each word: either manually tagged training examples or a small number of surefire decision rules (e.g., 'play' in the context of 'bass' almost always indicates the musical instrument). The seeds are used to train an initial classifier, using any supervised method. This classifier is then used on the untagged portion of the corpus to extract a larger training set, in which only the most confident classifications are included. The process repeats, each new classifier being trained on a successively larger training corpus, until the whole corpus is consumed, or until a given maximum number of iterations is reached.

Other semi-supervised techniques use large quantities of untagged corpora to provide co-occurrence information that supplements the tagged corpora. These techniques have the potential to help in the adaptation of supervised models to different domains.

Also, an ambiguous word in one language is often translated into different words in a second language depending on the sense of the word. Word-aligned bilingual corpora have been used to infer cross-lingual sense distinctions, a kind of semi-supervised system.

Unsupervised methods[link]

Unsupervised learning is the greatest challenge for WSD researchers. The underlying assumption is that similar senses occur in similar contexts, and thus senses can be induced from text by clustering word occurrences using some measure of similarity of context,^[24] a task referred to as word sense induction or discrimination. Then, new occurrences of the word can be classified into the closest induced clusters/senses. Performance has been lower than other methods, above, but comparisons are difficult since senses induced must be mapped to a known dictionary of word senses. If a mapping to a set of dictionary senses is not desired, cluster-based evaluations (including measures of entropy and purity) can be performed. Alternatively, word sense induction methods can be tested and compared within an application. For instance, it has been shown that word sense induction improves Web search result clustering by increasing the quality of result clusters and the degree diversification of result lists.^[25] It is hoped that unsupervised learning will overcome the knowledge acquisition bottleneck because they are not dependent on manual effort.

Other approaches[link]

Other approaches may vary differently in their methods:

• Identification of dominant word senses;^[26][27][28]
• Domain-driven disambiguation;^[29][30]
• WSD using Cross-Lingual Evidence.^[31][32]

Local impediments and summary[link]

The knowledge acquisition bottleneck is perhaps the major impediment to solving the WSD problem. Unsupervised methods rely on knowledge about word senses, which is barely formulated in dictionaries and lexical databases. Supervised methods depend crucially on the existence of manually annotated examples for every word sense, a requisite that can so far be met only for a handful of words for testing purposes, as it is done in the Senseval exercises.

Therefore, one of the most promising trends in WSD research is using the largest corpus ever accessible, the World Wide Web, to acquire lexical information automatically.^[33] WSD has been traditionally understood as an intermediate language engineering technology which could improve applications such as information retrieval (IR). In this case, however, the reverse is also true: Web search engines implement simple and robust IR techniques that can be successfully used when mining the Web for information to be employed in WSD. Therefore, the lack of training data provoked appearing some new algorithms and techniques described here:

External knowledge sources[link]

Knowledge is a fundamental component of WSD. Knowledge sources provide data which are essential to associate senses with words. They can vary from corpora of texts, either unlabeled or annotated with word senses, to machine-readable dictionaries, thesauri, glossaries, ontologies, etc. They can be^[34][35] classified as follows:

1. Structured:
   • Thesauri
   • Machine-readable dictionaries (MRDs)
   • Ontologies
2. Unstructured:
   • Corpora: raw corpora and sense-annotated corpora
   • Collocation resources
   • Other resources (such as word frequency lists, stoplists, domain labels,^[36] etc.)

Evaluation[link]

Comparing and evaluating different WSD systems is extremely difficult, because of the different test sets, sense inventories, and knowledge resources adopted. Before the organization of specific evaluation campaigns most systems were assessed on in-house, often small-scale, data sets. In order to test one's algorithm, developers should spend their time to annotate all word occurrences. And comparing methods even on the same corpus is not eligible if there is different sense inventories.

In order to define common evaluation datasets and procedures, public evaluation campaigns have been organized. Senseval (now renamed SemEval) is an international word sense disambiguation competition, held every three years since 1998: Senseval-1 (1998), Senseval-2 (2001), Senseval-3 (2004), and its successor, SemEval (2007). The objective of the competition is to organize different lectures, preparing and hand-annotating corpus for testing systems, perform a comparative evaluation of WSD systems in several kinds of tasks, including all-words and lexical sample WSD for different languages, and, more recently, new tasks such as semantic role labeling, gloss WSD, lexical substitution, etc. The systems submitted for evaluation to these competitions usually integrate different techniques and often combine supervised and knowledge-based methods (especially for avoiding bad performance in lack of training examples).

Task Design Choices[link]

Sense Inventories. During the first Senseval workshop the HECTOR sense inventory was adopted. The reason for adopting a previously unknown sense inventory was mainly to avoid the use of popular fine-grained word senses (such as WordNet), which could make the experiments unfair or biased. However, given the lack of coverage of such inventories, since the second Senseval workshop the WordNet sense inventory has been adopted.

A set of testing words. Comparison of methods can be divided in 2 groups by amount of words to test. The difference consists in the amount of analysis and processing:

• all-words task implies disambiguating all the words of the text
• lexical sample consists in disambiguating some previously chosen target words.

It is assumed that the former one is more realistic evaluation, although with very laborious testing of results. Initially only the latter was used in evaluation but later the former was included.

Lexical sample organizers had to choose samples on which the systems were to be tested. A criticism of earlier forays into lexical-sample WSD evaluation is that the lexical sample had been chosen according to the whim of the experimenter (or, to coincide with earlier experimenters' selections). For English Senseval, a sampling frame was devised in which words were classified according to their frequency (in the BNC) and their polysemy level (in WordNet). Also, inclusion POS-tagging problem was a matter of discussion and it was decided that samples should be words with known part of speech and some indeterminants (for ex. 15 noun tasks, 13 verb tasks, 8 adjectives, and 5 indeterminates).

Baselines. For comparison purposes, known, yet simple, algorithms named baselines are used. These include different variants of Lesk algorithm or most frequent sense algorithm.

Sense inventory. WSD exercises require a dictionary, to specify the word senses which are to be disambiguated, and a corpus of language data to be disambiguated. WordNet is the most popular example of sense inventory. The reason for adopting the HECTOR database during Senseval-1 was that the WordNet inventory was already publicly available.^[37]

Evaluation measures. During the evaluation of WSD systems two main performance measures are used:

• Precision: the fraction of system assignments made that are correct
• Recall: the fraction of total word instances correctly assigned by a system

If a system makes an assignment for every word, then precision and recall are the same, and can be called accuracy. This model has been extended to take into account systems that return a set of senses with weights for each occurrence.

Software[link]

• WordNet::SenseRelate, is a project that includes free, open source systems for word sense disambiguation and lexical sample sense disambiguation.
• UKB: Graph Base WSD, is a collection of programs for performing graph-based Word Sense Disambiguation and lexical similarity/relatedness using a pre-existing Lexical Knowledge Base (LKB).

See also[link]

• Ambiguity
• Lesk algorithm
• Lexical substitution
• Part-of-speech tagging
• Polysemy
• Semeval
• Syntactic ambiguity
• Word sense
• Word sense induction

Notes[link]

Works cited[link]

• Agirre, E.; Lopez de Lacalle, A.; Soroa, A. (2009) "Knowledge-based WSD on Specific Domains: Performing better than Generic Supervised WSD" Proc. of IJCAI http://www.ijcai.org/papers09/Papers/IJCAI09-251.pdf 
• Agirre, E.; M. Stevenson. 2006. Knowledge sources for WSD. In Word Sense Disambiguation: Algorithms and Applications, E. Agirre and P. Edmonds, Eds. Springer, New York, NY.
• Bar-Hillel, Y. (1964). Language and information. Reading, MA: Addison-Wesley. 
• Buitelaar, P.; B. Magnini, C. Strapparava and P. Vossen. 2006. Domain-specific WSD. In Word Sense Disambiguation: Algorithms and Applications, E. Agirre and P. Edmonds, Eds. Springer, New York, NY.
• Chan, Y. S.; H. T. Ng. 2005. Scaling up word sense disambiguation via parallel texts. In Proceedings of the 20th National Conference on Artificial Intelligence (AAAI, Pittsburgh, PA).
• Edmonds, P. 2000. Designing a task for SENSEVAL-2. Tech. note. University of Brighton, Brighton. U.K.
• Fellbaum, Christiane (1997) "Analysis of a handwriting task" Proc. of ANLP-97 Workshop on Tagging Text with Lexical Semantics: Why, What, and How? Washington D.C., USA 
• Gliozzo, A.; B. Magnini and C. Strapparava. 2004. Unsupervised domain relevance estimation for word sense disambiguation. In Proceedings of the 2004 Conference on Empirical Methods in Natural Language Processing (EMNLP, Barcelona, Spain).
• Ide, N.; T. Erjavec, D. Tufis. 2002. Sense discrimination with parallel corpora. In Proceedings of ACL Workshop on Word Sense Disambiguation: Recent Successes and Future Directions (Philadelphia, PA).
• Kilgarriff, A. 1997. I don't believe in word senses. Comput. Human. 31(2), pp. 91–113.
• Kilgarriff, A.; G. Grefenstette. 2003. Introduction to the special issue on the Web as corpus. Computational Linguistics 29(3), pp. 333–347
• Kilgarriff, Adam; Joseph Rosenzweig, English Senseval: Report and Results May–June, 2000, University of Brighton
• Lapata, M.; and F. Keller. 2007. An information retrieval approach to sense ranking. In Proceedings of the Human Language Technology Conference of the North American Chapter of the Association for Computational Linguistics (HLT-NAACL, Rochester, NY).
• Lenat, D. "Computers versus Common Sense". http://www.youtube.com/watch?v=KSrUHGaUE_c. Retrieved 2008-12-10.  (GoogleTachTalks on YouTube)
• Lenat, D.; R. V. Guha. 1989. Building Large Knowledge-Based Systems, Addison-Wesley
• Lesk; M. 1986. Automatic sense disambiguation using machine readable dictionaries: How to tell a pine cone from an ice cream cone. In Proc. of SIGDOC-86: 5th International Conference on Systems Documentation, Toronto, Canada.
• Litkowski, K. C. 2005. Computational lexicons and dictionaries. In Encyclopaedia of Language and Linguistics (2nd ed.), K. R. Brown, Ed. Elsevier Publishers, Oxford, U.K.
• Magnini, B; G. Cavaglià. 2000. Integrating subject field codes into WordNet. In Proceedings of the 2nd Conference on Language Resources and Evaluation (LREC, Athens, Greece).
• McCarthy, D.; R. Koeling, J. Weeds, J. Carroll. 2007. Unsupervised acquisition of predominant word senses. Computational Linguistics 33(4): 553–590.
• McCarthy, D.; R. Navigli. 2009. The English Lexical Substitution Task, Language Resources and Evaluation, 43(2), Springer.
• Mihalcea, R. 2007. Using Wikipedia for Automatic Word Sense Disambiguation. In Proc. of the North American Chapter of the Association for Computational Linguistics (NAACL 2007), Rochester, April 2007.
• Mohammad, S; G. Hirst. 2006. Determining word sense dominance using a thesaurus. In Proceedings of the 11th Conference on European chapter of the Association for Computational Linguistics (EACL, Trento, Italy).
• Navigli, R. 2006. Meaningful Clustering of Senses Helps Boost Word Sense Disambiguation Performance. Proc. of the 44th Annual Meeting of the Association for Computational Linguistics joint with the 21st International Conference on Computational Linguistics (COLING-ACL 2006), Sydney, Australia.
• Navigli, R.; G. Crisafulli. Inducing Word Senses to Improve Web Search Result Clustering. Proc. of the 2010 Conference on Empirical Methods in Natural Language Processing (EMNLP 2010), MIT Stata Center, Massachusetts, USA.
• Navigli, R.; M. Lapata. An Experimental Study of Graph Connectivity for Unsupervised Word Sense Disambiguation. IEEE Transactions on Pattern Analysis and Machine Intelligence (TPAMI), 32(4), IEEE Press, 2010.
• Navigli, R.; K. Litkowski, O. Hargraves. 2007. SemEval-2007 Task 07: Coarse-Grained English All-Words Task. Proc. of Semeval-2007 Workshop (SemEval), in the 45th Annual Meeting of the Association for Computational Linguistics (ACL 2007), Prague, Czech Republic.
• Navigli, R.;P. Velardi. 2005. Structural Semantic Interconnections: a Knowledge-Based Approach to Word Sense Disambiguation. IEEE Transactions on Pattern Analysis and Machine Intelligence (TPAMI), 27(7).
• Palmer, M.; O. Babko-Malaya and H. T. Dang. 2004. Different sense granularities for different applications. In Proceedings of the 2nd Workshop on Scalable Natural Language Understanding Systems in HLT/NAACL (Boston, MA).
• Ponzetto, S. P.; R. Navigli. Knowledge-rich Word Sense Disambiguation rivaling supervised systems. In Proc. of the 48th Annual Meeting of the Association for Computational Linguistics (ACL), 2010.
• Pradhan, S.; E. Loper, D. Dligach, M. Palmer. 2007. SemEval-2007 Task 17: English lexical sample, SRL and all words. Proc. of Semeval-2007 Workshop (SEMEVAL), in the 45th Annual Meeting of the Association for Computational Linguistics (ACL 2007), Prague, Czech Republic.
• Schütze, H. 1998. Automatic word sense discrimination. Computational Linguistics, 24(1): 97–123.
• Snow, R.; S. Prakash, D. Jurafsky, A. Y. Ng. 2007. Learning to Merge Word Senses, Proceedings of the 2007 Joint Conference on Empirical Methods in Natural Language Processing and Computational Natural Language Learning (EMNLP-CoNLL).
• Snyder, B.; M. Palmer. 2004. The English all-words task. In Proc. of the 3rd International Workshop on the Evaluation of Systems for the Semantic Analysis of Text (Senseval-3), Barcelona, Spain.
• Weaver, Warren (1949). "Translation". In Locke, W.N.; Booth, A.D.. Machine Translation of Languages: Fourteen Essays. Cambridge, MA: MIT Press. http://www.hutchinsweb.me.uk/MTNI-22-1999.pdf. 
• Wilks, Y.; B. Slator, L. Guthrie. 1996. Electric Words: dictionaries, computers and meanings. Cambridge, MA: MIT Press.
• Yarowsky, D. Word-sense disambiguation using statistical models of Roget's categories trained on large corpora. In Proc. of the 14th conference on Computational linguistics (COLING), 1992.
• Yarowsky, D. 1995. Unsupervised word sense disambiguation rivaling supervised methods. In Proc. of the 33rd Annual Meeting of the Association for Computational Linguistics.

External links and suggested reading[link]

Look up disambiguation in Wiktionary, the free dictionary.

• Computational Linguistics Special Issue on Word Sense Disambiguation (1998)
• Evaluation Exercises for Word Sense Disambiguation The de-facto standard benchmarks for WSD systems.
• Roberto Navigli. Word Sense Disambiguation: A Survey, ACM Computing Surveys, 41(2), 2009, pp. 1–69. An up-to-date state of the art of the field.
• Word Sense Disambiguation as defined in Scholarpedia
• Word Sense Disambiguation: The State of the Art (PDF) A comprehensive overview By Prof. Nancy Ide & Jean Véronis (1998).
• Word Sense Disambiguation Tutorial, by Rada Mihalcea and Ted Pedersen (2005).
• Word Sense Disambiguation: Algorithms and Applications, edited by Eneko Agirre and Philip Edmonds (2006), Springer. Covers the entire field with chapters contributed by leading researchers. www.wsdbook.org site of the book
• Bar-Hillel, Yehoshua. 1964. Language and Information. New York: Addison-Wesley.
• Edmonds, Philip & Adam Kilgarriff. 2002. Introduction to the special issue on evaluating word sense disambiguation systems. Journal of Natural Language Engineering, 8(4):279-291.
• Edmonds, Philip. 2005. Lexical disambiguation. The Elsevier Encyclopedia of Language and Linguistics, 2nd Ed., ed. by Keith Brown, 607-23. Oxford: Elsevier.
• Ide, Nancy & Jean Véronis. 1998. Word sense disambiguation: The state of the art. Computational Linguistics, 24(1):1-40.
• Jurafsky, Daniel & James H. Martin. 2000. Speech and Language Processing. New Jersey, USA: Prentice Hall.
• Litkowski, K. C. 2005. Computational lexicons and dictionaries. In Encyclopaedia of Language and Linguistics (2nd ed.), K. R. Brown, Ed. Elsevier Publishers, Oxford, U.K., 753–761.
• Manning, Christopher D. & Hinrich Schütze. 1999. Foundations of Statistical Natural Language Processing. Cambridge, MA: MIT Press. http://nlp.stanford.edu/fsnlp/
• Mihalcea, Rada. 2007. Word sense disambiguation. Encyclopedia of Machine Learning. Springer-Verlag.
• Resnik, Philip and David Yarowsky. 2000. Distinguishing systems and distinguishing senses: New evaluation methods for word sense disambiguation, Natural Language Engineering, 5(2):113-133. http://www.cs.jhu.edu/~yarowsky/pubs/nle00.ps
• Yarowsky, David. 2001. Word sense disambiguation. Handbook of Natural Language Processing, ed. by Dale et al., 629-654. New York: Marcel Dekker.

Barack Obama
44th President of the United States
Incumbent
Assumed office January 20, 2009
Vice President	Joe Biden
Preceded by	George W. Bush
United States Senator from Illinois
In office January 3, 2005 – November 16, 2008
Preceded by	Peter Fitzgerald
Succeeded by	Roland Burris
Member of the Illinois Senate from the 13th District
In office January 8, 1997 – November 4, 2004
Preceded by	Alice Palmer
Succeeded by	Kwame Raoul
Personal details
Born	Barack Hussein Obama II (1961-08-04) August 4, 1961 (age 50)[1] Honolulu, Hawaii, U.S.[2]
Political party	Democratic
Spouse(s)	Michelle Robinson (1992–present)
Children	Malia (born 1998) Sasha (born 2001)
Residence	White House (Official) Chicago, Illinois (Private)
Alma mater	Occidental College Columbia University (B.A.) Harvard Law School (J.D.)
Profession	Community organizer Lawyer Constitutional law professor Author
Religion	Christianity[3]
Awards	Nobel Peace Prize
Signature
Website	barackobama.com

	This article is part of a series on Barack Obama
Background Illinois Senate US Senate Political positions Public image Family 2008 primaries Obama–Biden campaign Transition Inauguration Electoral history Presidency Timeline '09 '10 '11 '12 First 100 days Nobel Peace Prize Re-election campaign

Barack Hussein Obama II (ⁱ/bəˈrɑːk huːˈseɪn oʊˈbɑːmə/; born August 4, 1961) is the 44th and current President of the United States. He is the first African American to hold the office. In January 2005, Obama was sworn in as a U.S. Senator in the state of Illinois. He would hold this office until November 2008, when he resigned following his victory in the 2008 presidential election.

Born in Honolulu, Hawaii, Obama is a graduate of Columbia University and Harvard Law School, where he was the president of the Harvard Law Review. He was a community organizer in Chicago before earning his law degree. He worked as a civil rights attorney in Chicago and taught constitutional law at the University of Chicago Law School from 1992 to 2004. He served three terms representing the 13th District in the Illinois Senate from 1997 to 2004.

Following an unsuccessful bid against the Democratic incumbent for a seat in the United States House of Representatives in 2000, Obama ran for the United States Senate in 2004. Several events brought him to national attention during the campaign, including his victory in the March 2004 Illinois Democratic primary for the Senate election and his keynote address at the Democratic National Convention in July 2004. He won election to the U.S. Senate in Illinois in November 2004. His presidential campaign began in February 2007, and after a close campaign in the 2008 Democratic Party presidential primaries against Hillary Rodham Clinton, he won his party's nomination. In the 2008 presidential election, he defeated Republican nominee John McCain, and was inaugurated as president on January 20, 2009. Nine months later, Obama was named the 2009 Nobel Peace Prize laureate. In April 2011, he announced that he would be running for re-election in 2012.

As president, Obama signed economic stimulus legislation in the form of the American Recovery and Reinvestment Act of 2009 and the Tax Relief, Unemployment Insurance Reauthorization, and Job Creation Act of 2010. Other domestic policy initiatives include the Patient Protection and Affordable Care Act, the Dodd–Frank Wall Street Reform and Consumer Protection Act, the Don't Ask, Don't Tell Repeal Act of 2010, and the Budget Control Act of 2011. In May 2012, he became the first sitting U.S. president to openly support legalizing same-sex marriage. In foreign policy, he ended the war in Iraq, increased troop levels in Afghanistan, signed the New START arms control treaty with Russia, ordered U.S. involvement in the 2011 Libya military intervention, and ordered the military operation that resulted in the death of Osama bin Laden.

Early life and career[link]

Obama was born on August 4, 1961, at Kapiʻolani Maternity & Gynecological Hospital (now Kapiʻolani Medical Center for Women and Children) in Honolulu, Hawaii,^[2][4][5] and is the first President to have been born in Hawaii.^[6] His mother, Stanley Ann Dunham, was born in Wichita, Kansas, and was of mostly English ancestry,^[7] along with Scottish, Irish, German, and Swiss.^{[8][9][10][11][12]} His father, Barack Obama, Sr., was a Luo from Nyang’oma Kogelo, Nyanza Province, Kenya. Obama's parents met in 1960 in a Russian class at the University of Hawaiʻi at Mānoa, where his father was a foreign student on scholarship.^[13][14] The couple married on February 2, 1961,^[15] separated when Obama Sr. went to Harvard University on scholarship, and divorced in 1964.^[13] Obama Sr. remarried and returned to Kenya, visiting Barack in Hawaii only once, in 1971. He died in an automobile accident in 1982.^[16]

After her divorce, Dunham married Indonesian Lolo Soetoro, who was attending college in Hawaii. When Suharto, a military leader in Soetoro's home country, came to power in 1967, all Indonesian students studying abroad were recalled, and the family moved to the Menteng neighborhood of Jakarta.^[4][17] From ages six to ten, Obama attended local schools in Jakarta, including Besuki Public School and St. Francis of Assisi School.^[18]

In 1971, Obama returned to Honolulu to live with his maternal grandparents, Madelyn and Stanley Armour Dunham, and with the aid of a scholarship attended Punahou School, a private college preparatory school, from fifth grade until his graduation from high school in 1979.^[19] Obama's mother returned to Hawaii in 1972, remaining there until 1977 when she went back to Indonesia to work as an anthropological field worker. She finally returned to Hawaii in 1994 and lived there for one year before dying of ovarian cancer.^[15][20]

Of his early childhood, Obama recalled, "That my father looked nothing like the people around me—that he was black as pitch, my mother white as milk—barely registered in my mind."^[14] He described his struggles as a young adult to reconcile social perceptions of his multiracial heritage.^[21] Reflecting later on his years in Honolulu, Obama wrote: "The opportunity that Hawaii offered—to experience a variety of cultures in a climate of mutual respect—became an integral part of my world view, and a basis for the values that I hold most dear."^[22] Obama has also written and talked about using alcohol, marijuana, and cocaine during his teenage years to "push questions of who I was out of my mind."^[23] At the 2008 Civil Forum on the Presidency, Obama described his high-school drug use as a great moral failure.^[24]

Following high school, Obama moved to Los Angeles in 1979 to attend Occidental College. In February 1981, he made his first public speech, calling for Occidental to divest from South Africa in response to its policy of apartheid.^[25] In mid-1981, Obama traveled to Indonesia to visit his mother and sister Maya, and visited the families of college friends in Pakistan and India for three weeks.^[25] Later in 1981, he transferred to Columbia University in New York City, where he majored in political science with a specialty in international relations^[26] and graduated with a Bachelor of Arts in 1983. He worked for a year at the Business International Corporation,^[27] then at the New York Public Interest Research Group.^[28][29]

Chicago community organizer and Harvard Law School[link]

Two years after graduating, Obama was hired in Chicago as director of the Developing Communities Project (DCP), a church-based community organization originally comprising eight Catholic parishes in Roseland, West Pullman, and Riverdale on Chicago's South Side. He worked there as a community organizer from June 1985 to May 1988.^[29][30] He helped set up a job training program, a college preparatory tutoring program, and a tenants' rights organization in Altgeld Gardens.^[31] Obama also worked as a consultant and instructor for the Gamaliel Foundation, a community organizing institute.^[32] In mid-1988, he traveled for the first time in Europe for three weeks and then for five weeks in Kenya, where he met many of his paternal relatives for the first time.^[33] He returned to Kenya in August 2006 for a visit to his father's birthplace, a village near Kisumu in rural western Kenya.^[34]

In late 1988, Obama entered Harvard Law School. He was selected as an editor of the Harvard Law Review at the end of his first year,^[35] and president of the journal in his second year.^[31][36] During his summers, he returned to Chicago, where he worked as an associate at the law firms of Sidley Austin in 1989 and Hopkins & Sutter in 1990.^[37] After graduating with a J.D. magna cum laude^[38] from Harvard in 1991, he returned to Chicago.^[35] Obama's election as the first black president of the Harvard Law Review gained national media attention^[31][36] and led to a publishing contract and advance for a book about race relations,^[39] which evolved into a personal memoir. The manuscript was published in mid-1995 as Dreams from My Father.^[39]

University of Chicago Law School and civil rights attorney[link]

In 1991, Obama accepted a two-year position as Visiting Law and Government Fellow at the University of Chicago Law School to work on his first book.^[39][40] He then taught at the University of Chicago Law School for twelve years—as a Lecturer from 1992 to 1996, and as a Senior Lecturer from 1996 to 2004—teaching constitutional law.^[41]

From April to October 1992, Obama directed Illinois's Project Vote, a voter registration campaign with ten staffers and seven hundred volunteer registrars; it achieved its goal of registering 150,000 of 400,000 unregistered African Americans in the state, leading Crain's Chicago Business to name Obama to its 1993 list of "40 under Forty" powers to be.^[42] In 1993, he joined Davis, Miner, Barnhill & Galland, a 13-attorney law firm specializing in civil rights litigation and neighborhood economic development, where he was an associate for three years from 1993 to 1996, then of counsel from 1996 to 2004. His law license became inactive in 2002.^[43]

From 1994 to 2002, Obama served on the boards of directors of the Woods Fund of Chicago, which in 1985 had been the first foundation to fund the Developing Communities Project; and of the Joyce Foundation.^[29] He served on the board of directors of the Chicago Annenberg Challenge from 1995 to 2002, as founding president and chairman of the board of directors from 1995 to 1999.^[29]

Legislative career: 1997–2008[link]

State Senator: 1997–2004[link]

Obama was elected to the Illinois Senate in 1996, succeeding State Senator Alice Palmer as Senator from Illinois's 13th District, which at that time spanned Chicago South Side neighborhoods from Hyde Park – Kenwood south to South Shore and west to Chicago Lawn.^[44] Once elected, Obama gained bipartisan support for legislation that reformed ethics and health care laws.^[45] He sponsored a law that increased tax credits for low-income workers, negotiated welfare reform, and promoted increased subsidies for childcare.^[46] In 2001, as co-chairman of the bipartisan Joint Committee on Administrative Rules, Obama supported Republican Governor Ryan's payday loan regulations and predatory mortgage lending regulations aimed at averting home foreclosures.^[47]

Obama was reelected to the Illinois Senate in 1998, defeating Republican Yesse Yehudah in the general election, and was reelected again in 2002.^[48] In 2000, he lost a Democratic primary run for the U.S. House of Representatives to four-term incumbent Bobby Rush by a margin of two to one.^[49]

In January 2003, Obama became chairman of the Illinois Senate's Health and Human Services Committee when Democrats, after a decade in the minority, regained a majority.^[50] He sponsored and led unanimous, bipartisan passage of legislation to monitor racial profiling by requiring police to record the race of drivers they detained, and legislation making Illinois the first state to mandate videotaping of homicide interrogations.^[46][51] During his 2004 general election campaign for U.S. Senate, police representatives credited Obama for his active engagement with police organizations in enacting death penalty reforms.^[52] Obama resigned from the Illinois Senate in November 2004 following his election to the U.S. Senate.^[53]

U.S. Senate campaign[link]

County results of the 2004 U.S. Senate race in Illinois. Counties in blue were won by Obama.

In May 2002, Obama commissioned a poll to assess his prospects in a 2004 U.S. Senate race; he created a campaign committee, began raising funds, and lined up political media consultant David Axelrod by August 2002. Obama formally announced his candidacy in January 2003.^[54]

Obama was an early opponent of the George W. Bush administration's 2003 invasion of Iraq.^[55] On October 2, 2002, the day President Bush and Congress agreed on the joint resolution authorizing the Iraq War,^[56] Obama addressed the first high-profile Chicago anti-Iraq War rally,^[57] and spoke out against the war.^[58] He addressed another anti-war rally in March 2003 and told the crowd that "it's not too late" to stop the war.^[59]

Decisions by Republican incumbent Peter Fitzgerald and his Democratic predecessor Carol Moseley Braun to not participate in the election resulted in wide-open Democratic and Republican primary contests involving fifteen candidates.^[60] In the March 2004 primary election, Obama won in an unexpected landslide—which overnight made him a rising star within the national Democratic Party, started speculation about a presidential future, and led to the reissue of his memoir, Dreams from My Father.^[61] In July 2004, Obama delivered the keynote address at the 2004 Democratic National Convention,^[62] seen by 9.1 million viewers. His speech was well received and elevated his status within the Democratic Party.^[63]

Obama's expected opponent in the general election, Republican primary winner Jack Ryan, withdrew from the race in June 2004.^[64] Six weeks later, Alan Keyes accepted the Republican nomination to replace Ryan.^[65] In the November 2004 general election, Obama won with 70 percent of the vote.^[66]

U.S. Senator: 2005–2008[link]

Obama was sworn in as a senator on January 3, 2005,^[67] becoming the only Senate member of the Congressional Black Caucus.^[68] CQ Weekly characterized him as a "loyal Democrat" based on analysis of all Senate votes in 2005–2007. Obama announced on November 13, 2008, that he would resign his Senate seat on November 16, 2008, before the start of the lame-duck session, to focus on his transition period for the presidency.^[69]

Legislation[link]

Obama cosponsored the Secure America and Orderly Immigration Act.^[70] He introduced two initiatives that bore his name: Lugar–Obama, which expanded the Nunn–Lugar cooperative threat reduction concept to conventional weapons;^[71] and the Federal Funding Accountability and Transparency Act of 2006, which authorized the establishment of USAspending.gov, a web search engine on federal spending.^[72] On June 3, 2008, Senator Obama—along with Senators Tom Carper, Tom Coburn, and John McCain—introduced follow-up legislation: Strengthening Transparency and Accountability in Federal Spending Act of 2008.^[73]

Obama sponsored legislation that would have required nuclear plant owners to notify state and local authorities of radioactive leaks, but the bill failed to pass in the full Senate after being heavily modified in committee.^[74] Regarding tort reform, Obama voted for the Class Action Fairness Act of 2005 and the FISA Amendments Act of 2008, which grants immunity from civil liability to telecommunications companies complicit with NSA warrantless wiretapping operations.^[75]

Obama and U.S. Sen. Richard Lugar (R-IN) visit a Russian facility for dismantling mobile-missiles (August 2005).^[76]

In December 2006, President Bush signed into law the Democratic Republic of the Congo Relief, Security, and Democracy Promotion Act, marking the first federal legislation to be enacted with Obama as its primary sponsor.^[77] In January 2007, Obama and Senator Feingold introduced a corporate jet provision to the Honest Leadership and Open Government Act, which was signed into law in September 2007.^[78] Obama also introduced Deceptive Practices and Voter Intimidation Prevention Act, a bill to criminalize deceptive practices in federal elections,^[79] and the Iraq War De-Escalation Act of 2007,^[80] neither of which was signed into law.

Later in 2007, Obama sponsored an amendment to the Defense Authorization Act to add safeguards for personality-disorder military discharges.^[81] This amendment passed the full Senate in the spring of 2008.^[82] He sponsored the Iran Sanctions Enabling Act supporting divestment of state pension funds from Iran's oil and gas industry, which has not passed committee; and co-sponsored legislation to reduce risks of nuclear terrorism.^[83] Obama also sponsored a Senate amendment to the State Children's Health Insurance Program, providing one year of job protection for family members caring for soldiers with combat-related injuries.^[84]

Committees[link]

Obama held assignments on the Senate Committees for Foreign Relations, Environment and Public Works, and Veterans' Affairs through December 2006.^[85] In January 2007, he left the Environment and Public Works committee and took additional assignments with Health, Education, Labor, and Pensions and Homeland Security and Governmental Affairs.^[86] He also became Chairman of the Senate's subcommittee on European Affairs.^[87] As a member of the Senate Foreign Relations Committee, Obama made official trips to Eastern Europe, the Middle East, Central Asia and Africa. He met with Mahmoud Abbas before Abbas became President of the Palestinian National Authority, and gave a speech at the University of Nairobi in which he condemned corruption within the Kenyan government.^[88]

Presidential campaigns[link]

2008 presidential campaign[link]

Obama stands on stage with his wife and daughters just before announcing his presidential candidacy in Springfield, Illinois, February 10, 2007.

President George W. Bush meets with President-elect Obama in the Oval Office on November 10, 2008.

On February 10, 2007, Obama announced his candidacy for President of the United States in front of the Old State Capitol building in Springfield, Illinois.^[89][90] The choice of the announcement site was viewed as symbolic because it was also where Abraham Lincoln delivered his historic "House Divided" speech in 1858.^[89][91] Obama emphasized issues of rapidly ending the Iraq War, increasing energy independence, and providing universal health care,^[92] in a campaign that projected themes of "hope" and "change".^[93]

A large number of candidates entered the Democratic Party presidential primaries. The field narrowed to a duel between Obama and Senator Hillary Rodham Clinton after early contests, with the race remaining close throughout the primary process but with Obama gaining a steady lead in pledged delegates due to better long-range planning, superior fundraising, dominant organizing in caucus states, and better exploitation of delegate allocation rules.^[94] On June 7, 2008, Clinton ended her campaign and endorsed Obama.^[95]

On August 23, Obama announced his selection of Delaware Senator Joe Biden as his vice presidential running mate.^[96] Biden was selected from a field speculated to include former Indiana Governor and Senator Evan Bayh and Virginia Governor Tim Kaine.^[97] At the Democratic National Convention in Denver, Colorado, Hillary Clinton called for her supporters to endorse Obama, and she and Bill Clinton gave convention speeches in his support.^[98] Obama delivered his acceptance speech, not at the center where the Democratic National Convention was held, but at Invesco Field at Mile High to a crowd of over 75,000; the speech was viewed by over 38 million people worldwide.^[99][100]

During both the primary process and the general election, Obama's campaign set numerous fundraising records, particularly in the quantity of small donations.^[101] On June 19, 2008, Obama became the first major-party presidential candidate to turn down public financing in the general election since the system was created in 1976.^[102]

McCain was nominated as the Republican candidate and the two engaged in three presidential debates in September and October 2008.^[103] On November 4, Obama won the presidency with 365 electoral votes to 173 received by McCain.^[104] Obama won 52.9 percent of the popular vote to McCain's 45.7 percent.^[105] He became the first African American to be elected president.^[106] Obama delivered his victory speech before hundreds of thousands of supporters in Chicago's Grant Park.^[107]

2012 presidential campaign[link]

On April 4, 2011, Obama announced his re-election campaign for 2012 in a video titled "It Begins with Us" that he posted on his website and filed election papers with the Federal Election Commission.^{[108][109][110]} As the incumbent president he ran almost unopposed in the Democratic Party presidential primaries,^[111] and on April 3, 2012, Obama had secured the 2778 convention delegates needed to win the Democratic nomination.^[112]

Presidency[link]

First days[link]

Barack Obama takes the oath of office as President of the United States.

The inauguration of Barack Obama as the 44th President, and Joe Biden as Vice President, took place on January 20, 2009. In his first few days in office, Obama issued executive orders and presidential memoranda directing the U.S. military to develop plans to withdraw troops from Iraq.^[113] He ordered the closing of the Guantanamo Bay detention camp,^[114] but Congress prevented the closure by refusing to appropriate the required funds.^{[115][116][117]} Obama reduced the secrecy given to presidential records,^[118] and changed procedures to promote disclosure under the Freedom of Information Act.^[119] He also reversed George W. Bush's ban on federal funding to foreign establishments that allow abortions.^[120]

Domestic policy[link]

The first bill signed into law by Obama was the Lilly Ledbetter Fair Pay Act of 2009, relaxing the statute of limitations for equal-pay lawsuits.^[121] Five days later, he signed the reauthorization of the State Children's Health Insurance Program (SCHIP) to cover an additional 4 million uninsured children.^[122] In March 2009, Obama reversed a Bush-era policy which had limited funding of embryonic stem cell research and pledged to develop "strict guidelines" on the research.^[123]

Barack Obama speaking at Joint session of Congress with Vice President Joe Biden and House Speaker Nancy Pelosi on February 24, 2009

Obama appointed two women to serve on the Supreme Court in the first two years of his Presidency. Sonia Sotomayor, nominated by Obama on May 26, 2009, to replace retiring Associate Justice David Souter, was confirmed on August 6, 2009,^[124] becoming the first Hispanic to be a Supreme Court Justice.^[125] Elena Kagan, nominated by Obama on May 10, 2010, to replace retiring Associate Justice John Paul Stevens, was confirmed on August 5, 2010, bringing the number of women sitting simultaneously on the Court to three, for the first time in American history.^[126]

On September 30, 2009, the Obama administration proposed new regulations on power plants, factories and oil refineries in an attempt to limit greenhouse gas emissions and to curb global warming.^[127][128]

On October 8, 2009, Obama signed the Matthew Shepard and James Byrd, Jr. Hate Crimes Prevention Act, a measure that expands the 1969 United States federal hate-crime law to include crimes motivated by a victim's actual or perceived gender, sexual orientation, gender identity, or disability.^[129][130]

On March 30, 2010, Obama signed the Health Care and Education Reconciliation Act, a reconciliation bill which ends the process of the federal government giving subsidies to private banks to give out federally insured loans, increases the Pell Grant scholarship award, and makes changes to the Patient Protection and Affordable Care Act.^[131][132]

In a major space policy speech in April 2010, Obama announced a planned change in direction at NASA, the U.S. space agency. He ended plans for a return of human spaceflight to the moon and development of the Ares I rocket, Ares V rocket and Constellation program, in favor of funding Earth science projects, a new rocket type, and research and development for an eventual manned mission to Mars, and ongoing missions to the International Space Station.^[133]

On December 22, 2010, Obama signed the Don't Ask, Don't Tell Repeal Act of 2010, fulfilling a key promise made in the 2008 presidential campaign^[134][135] to end the Don't ask, don't tell policy of 1993 that had prevented gay and lesbian people from serving openly in the United States Armed Forces.^[136]

President Obama's 2011 State of the Union Address focused on themes of education and innovation, stressing the importance of innovation economics to make the United States more competitive globally. He spoke of a five-year freeze in domestic spending, eliminating tax breaks for oil companies and reversing tax cuts for wealthy Americans, banning congressional earmarks, and reducing healthcare costs. He promised that the United States would have one million electric vehicles on the road by 2015 and would be 80% reliant on "clean" electricity.^[137][138]

As a candidate for the Illinois state senate Obama had said in 1996 that he favored legalizing same-sex marriage;^[139] but by the time of his run for the U.S. senate in 2004, he said that while he supported civil unions and domestic partnerships for same-sex partners, for strategic reasons he opposed same-sex marriages.^[140] On May 9, 2012, shortly after the official launch of his campaign for re-election as president, Obama said his views had evolved, and he publicly affirmed his personal support for the legalization of same-sex marriage, becoming the first sitting U.S. president to do so.^[141][142]

Economic policy[link]

Obama presents his first weekly address as President of the United States on January 24, 2009, discussing the American Recovery and Reinvestment Act of 2009.

On February 17, 2009, Obama signed the American Recovery and Reinvestment Act of 2009, a $787 billion economic stimulus package aimed at helping the economy recover from the deepening worldwide recession.^[143] The act includes increased federal spending for health care, infrastructure, education, various tax breaks and incentives, and direct assistance to individuals,^[144] which is being distributed over the course of several years.

In March, Obama's Treasury Secretary, Timothy Geithner, took further steps to manage the financial crisis, including introducing the Public-Private Investment Program for Legacy Assets, which contains provisions for buying up to $2 trillion in depreciated real estate assets.^[145] Obama intervened in the troubled automotive industry^[146] in March 2009, renewing loans for General Motors and Chrysler to continue operations while reorganizing. Over the following months the White House set terms for both firms' bankruptcies, including the sale of Chrysler to Italian automaker Fiat^[147] and a reorganization of GM giving the U.S. government a temporary 60 percent equity stake in the company, with the Canadian government shouldering a 12 percent stake.^[148] In June 2009, dissatisfied with the pace of economic stimulus, Obama called on his cabinet to accelerate the investment.^[149] He signed into law the Car Allowance Rebate System, known colloquially as "Cash for Clunkers", that temporarily boosted the economy.^{[150][151][152]}

Although spending and loan guarantees from the Federal Reserve and the Treasury Department authorized by the Bush and Obama administrations totaled about $11.5 trillion, only $3 trillion had been spent by the end of November 2009.^[153] However, Obama and the Congressional Budget Office predicted that the 2010 budget deficit will be $1.5 trillion or 10.6 percent of the nation's gross domestic product (GDP) compared to the 2009 deficit of $1.4 trillion or 9.9 percent of GDP.^[154][155] For 2011, the administration predicted the deficit will slightly shrink to $1.34 trillion, while the 10-year deficit will increase to $8.53 trillion or 90 percent of GDP.^[156] The most recent increase in the U.S. debt ceiling to $16.4 trillion was signed into law on January 26, 2012.^[157] On August 2, 2011, after a lengthy congressional debate over whether to raise the nation's debt limit, Obama signed the bipartisan Budget Control Act of 2011. The legislation enforces limits on discretionary spending until 2021, establishes a procedure to increase the debt limit, creates a Congressional Joint Select Committee on Deficit Reduction to propose further deficit reduction with a stated goal of achieving at least $1.5 trillion in budgetary savings over 10 years, and establishes automatic procedures for reducing spending by as much as $1.2 trillion if legislation originating with the new joint select committee does not achieve such savings.^[158] By passing the legislation, Congress was able to prevent an unprecedented U.S. government default on its obligations.^[159]

Employment statistics (changes in unemployment rate and net jobs per month) during Obama's tenure as U.S. President^[160][161]

The unemployment rate rose in 2009, reaching a peak in October at 10.1 percent and averaging 10.0 percent in the fourth quarter. Following a decrease to 9.7 percent in the first quarter of 2010, the unemployment rate fell to 9.6 percent in the second quarter, where it remained for the rest of the year.^[162] Between February and December 2010, employment rose by 0.8 percent, which was less than the average of 1.9 percent experienced during comparable periods in the past four employment recoveries.^[163] GDP growth returned in the third quarter of 2009, expanding at a rate of 1.6 percent, followed by a 5.0 percent increase in the fourth quarter.^[164] Growth continued in 2010, posting an increase of 3.7 percent in the first quarter, with lesser gains throughout the rest of the year.^[164] In July 2010, the Federal Reserve expressed that although economic activity continued to increase, its pace had slowed, and Chairman Ben Bernanke stated that the economic outlook was "unusually uncertain."^[165] Overall, the economy expanded at a rate of 2.9 percent in 2010.^[166]

The Congressional Budget Office and a broad range of economists credit Obama's stimulus plan for economic growth.^[167][168] The CBO released a report stating that the stimulus bill increased employment by 1–2.1 million,^{[168][169][170][171]} while conceding that "It is impossible to determine how many of the reported jobs would have existed in the absence of the stimulus package."^[167] Although an April 2010 survey of members of the National Association for Business Economics showed an increase in job creation (over a similar January survey) for the first time in two years, 73 percent of 68 respondents believed that the stimulus bill has had no impact on employment.^[172]

Within a month of the 2010 midterm elections, Obama announced a compromise deal with the Congressional Republican leadership that included a temporary, two-year extension of the 2001 and 2003 income tax rates, a one-year payroll tax reduction, continuation of unemployment benefits, and a new rate and exemption amount for estate taxes.^[173] The compromise overcame opposition from some in both parties, and the resulting $858 billion Tax Relief, Unemployment Insurance Reauthorization, and Job Creation Act of 2010 passed with bipartisan majorities in both houses of Congress before Obama signed it on December 17, 2010.^[174]

Health care reform[link]

Barack Obama signs the Patient Protection and Affordable Care Act at the White House, March 23, 2010

Obama called for Congress to pass legislation reforming health care in the United States, a key campaign promise and a top legislative goal.^[175] He proposed an expansion of health insurance coverage to cover the uninsured, to cap premium increases, and to allow people to retain their coverage when they leave or change jobs. His proposal was to spend $900 billion over 10 years and include a government insurance plan, also known as the public option, to compete with the corporate insurance sector as a main component to lowering costs and improving quality of health care. It would also make it illegal for insurers to drop sick people or deny them coverage for pre-existing conditions, and require every American carry health coverage. The plan also includes medical spending cuts and taxes on insurance companies that offer expensive plans.^[176][177]

On July 14, 2009, House Democratic leaders introduced a 1,017-page plan for overhauling the U.S. health care system, which Obama wanted Congress to approve by the end of 2009.^[175] After much public debate during the Congressional summer recess of 2009, Obama delivered a speech to a joint session of Congress on September 9 where he addressed concerns over the proposals.^[178] In March 2009, Obama lifted a ban on stem cell research.^[179]

On November 7, 2009, a health care bill featuring the public option was passed in the House.^[180][181] On December 24, 2009, the Senate passed its own bill—without a public option—on a party-line vote of 60–39.^[182] On March 21, 2010, the Patient Protection and Affordable Care Act passed by the Senate in December was passed in the House by a vote of 219 to 212.^[183] Obama signed the bill into law on March 23, 2010.^[184]

The Patient Protection and Affordable Care Act includes health-related provisions to take effect over four years, including expanding Medicaid eligibility for people making up to 133 percent of the federal poverty level (FPL) starting in 2014,^[185] subsidizing insurance premiums for people making up to 400 percent of the FPL ($88,000 for family of four in 2010) so their maximum "out-of-pocket" payment for annual premiums will be from 2 to 9.5 percent of income,^[186][187] providing incentives for businesses to provide health care benefits, prohibiting denial of coverage and denial of claims based on pre-existing conditions, establishing health insurance exchanges, prohibiting annual coverage caps, and support for medical research. According to White House and Congressional Budget Office figures, the maximum share of income that enrollees would have to pay would vary depending on their income relative to the federal poverty level.^[186][188]

The costs of these provisions are offset by taxes, fees, and cost-saving measures, such as new Medicare taxes for those in high-income brackets, taxes on indoor tanning, cuts to the Medicare Advantage program in favor of traditional Medicare, and fees on medical devices and pharmaceutical companies;^[189] there is also a tax penalty for those who do not obtain health insurance, unless they are exempt due to low income or other reasons.^[190] In March, 2010, the Congressional Budget Office estimated that the net effect of both laws will be a reduction in the federal deficit by $143 billion over the first decade.^[191]

In March 2012, the Supreme Court heard arguments by a coalition of 26 states maintaining that it is unconstitutional to force individuals to buy health insurance.^[192]

Gulf of Mexico oil spill[link]

On April 20, 2010, an explosion destroyed an offshore drilling rig at the Macondo Prospect in the Gulf of Mexico, causing a major sustained oil leak. The well's operator, BP, initiated a containment and cleanup plan, and began drilling two relief wells intended to stop the flow. Obama visited the Gulf on May 2 among visits by members of his cabinet, and again on May 28 and June 4. On May 22, he announced a federal investigation and formed a bipartisan commission to recommend new safety standards, after a review by Secretary of the Interior Ken Salazar and concurrent Congressional hearings. On May 27, he announced a 6-month moratorium on new deepwater drilling permits and leases, pending regulatory review.^[193] As multiple efforts by BP failed, some in the media and public expressed confusion and criticism over various aspects of the incident, and stated a desire for more involvement by Obama and the federal government.^[194]

Foreign policy[link]

Barack Obama speaking on "A New Beginning" at Cairo University on June 4, 2009

In February and March, Vice President Joe Biden and Secretary of State Hillary Rodham Clinton made separate overseas trips to announce a "new era" in U.S. foreign relations with Russia and Europe, using the terms "break" and "reset" to signal major changes from the policies of the preceding administration.^[195] Obama attempted to reach out to Arab leaders by granting his first interview to an Arab cable TV network, Al Arabiya.^[196]

On March 19, Obama continued his outreach to the Muslim world, releasing a New Year's video message to the people and government of Iran.^[197] This attempt at outreach was rebuffed by the Iranian leadership.^[198] In April, Obama gave a speech in Ankara, Turkey, which was well received by many Arab governments.^[199] On June 4, 2009, Obama delivered a speech at Cairo University in Egypt calling for "a new beginning" in relations between the Islamic world and the United States and promoting Middle East peace.^[200]

On June 26, 2009, in response to the Iranian government's actions towards protesters following Iran's 2009 presidential election, Obama said: "The violence perpetrated against them is outrageous. We see it and we condemn it."^[201] On July 7, while in Moscow, he responded to a Vice President Biden comment on a possible Israeli military strike on Iran by saying: "We have said directly to the Israelis that it is important to try and resolve this in an international setting in a way that does not create major conflict in the Middle East."^[202]

British Prime Minister David Cameron and Barack Obama, during the 2010 G-20 Toronto summit.

On September 24, 2009, Obama became the first sitting U.S. president to preside over a meeting of the United Nations Security Council.^[203]

In March 2010, Obama took a public stance against plans by the government of Israeli Prime Minister Benjamin Netanyahu to continue building Jewish housing projects in predominantly Arab neighborhoods of East Jerusalem.^[204][205] During the same month, an agreement was reached with the administration of Russian President Dmitry Medvedev to replace the 1991 Strategic Arms Reduction Treaty with a new pact reducing the number of long-range nuclear weapons in the arsenals of both countries by about one-third.^[206] The New START treaty was signed by Obama and Medvedev in April 2010, and was ratified by the U.S. Senate in December 2010.^[207]

On December 6, 2011, he instructed agencies to consider LGBT rights when issuing financial aid to foreign countries.^[208]

Iraq War[link]

On February 27, 2009, Obama declared that combat operations in Iraq would end within 18 months. His remarks were made to a group of Marines preparing for deployment to Afghanistan. Obama said, "Let me say this as plainly as I can: By August 31, 2010, our combat mission in Iraq will end."^[209] The Obama administration scheduled the withdrawal of combat troops to be completed by August 2010, decreasing troops levels from 142,000 while leaving a transitional force of 35,000 to 50,000 in Iraq until the end of 2011. On August 19, 2010, the last United States combat brigade exited Iraq. The plan is to transition the mission of the remaining troops from combat operations to counter-terrorism and the training, equipping, and advising of Iraqi security forces.^[210][211] On August 31, 2010, Obama announced that the United States combat mission in Iraq was over.^[212] On October 21, 2011 President Obama announced that all U.S. troops would leave Iraq in time to be, "home for the holidays".^[213]

War in Afghanistan[link]

Early in his presidency, Obama moved to bolster U.S. troop strength in Afghanistan.^[214] He announced an increase to U.S. troop levels of 17,000 in February 2009 to "stabilize a deteriorating situation in Afghanistan", an area he said had not received the "strategic attention, direction and resources it urgently requires".^[215] He replaced the military commander in Afghanistan, General David D. McKiernan, with former Special Forces commander Lt. Gen. Stanley A. McChrystal in May 2009, indicating that McChrystal's Special Forces experience would facilitate the use of counterinsurgency tactics in the war.^[216] On December 1, 2009, Obama announced the deployment of an additional 30,000 military personnel to Afghanistan.^[217] He also proposed to begin troop withdrawals 18 months from that date.^[218][219] McChrystal was replaced by David Petraeus in June 2010, after McChrystal's staff criticized White House personnel in a magazine article.^[220]

Israel[link]

Obama meeting with Israeli President Shimon Peres, 2009

During the initial years of the Obama administration, the U.S. increased military cooperation with Israel, including a record number of U.S. troops participating in military exercises in the country, increased military aid, the re-establishment of the U.S.-Israeli Joint Political Military Group and the Defense Policy Advisory Group, and an increase in visits among high-level military officials of both countries, including Ehud Barak and Admiral Mike Mullen.^[221]

In 2011, the United States vetoed a Security Council resolution condemning Israeli settlements, with the United States being the only nation to do so.^[222] Obama supports the two-state solution to the Arab–Israeli conflict based on the 1967 borders with land swaps.^[223]

War in Libya[link]

In March 2011, as forces loyal to Muammar Gaddafi advanced on rebels across Libya, calls for a no-fly zone came from around the world, including Europe, the Arab League, and a resolution^[224] passed unanimously by the U.S. Senate.^[225] In response to the unanimous passage of United Nations Security Council Resolution 1973 on March 17, Gaddafi who had previously vowed to "show no mercy" to the citizens of Benghazi^[226]—announced an immediate cessation of military activities,^[227] yet reports came in that his forces continued shelling Misrata. The next day, on Obama's orders, the U.S. military took a lead role in air strikes to destroy the Libyan government's air defense capabilities in order to protect civilians and enforce a no-fly-zone,^[228] including the use of Tomahawk missiles, B-2 Spirits, and fighter jets.^{[229][230][231]} Six days later, on March 25, by unanimous vote of all of its 28 members, NATO took over leadership of the effort, dubbed Operation Unified Protector.^[232] Some Representatives^[233] questioned whether Obama had the constitutional authority to order military action in addition to questioning its cost, structure and aftermath.^[234][235]

Osama bin Laden[link]

Obama and the U.S. national security team gathered in the Situation Room to monitor the military operation resulting in the death of Osama bin Laden on May 1, 2011.

Starting with information received in July 2010, intelligence developed by the CIA over the next several months determined what they believed to be the location of Osama bin Laden in a large compound in Abbottabad, Pakistan, a suburban area 35 miles from Islamabad.^[236] CIA head Leon Panetta reported this intelligence to President Obama in March 2011.^[236] Meeting with his national security advisers over the course of the next six weeks, Obama rejected a plan to bomb the compound, and authorized a "surgical raid" to be conducted by United States Navy SEALs.^[236] The operation took place on May 1, 2011, resulting in the death of bin Laden and the seizure of papers and computer drives and disks from the compound.^[237][238] Bin Laden's body was identified through DNA testing,^[239] and buried at sea several hours later.^[240] Within minutes of the President's announcement from Washington, DC, late in the evening on May 1, there were spontaneous celebrations around the country as crowds gathered outside the White House, and at New York City's Ground Zero and Times Square.^[237][241] Reaction to the announcement was positive across party lines, including from former Presidents Bill Clinton and George W. Bush,^[242] and from many countries around the world.^[243]

2010 midterm election[link]

Obama called the November 2, 2010 election, where the Democratic Party lost 63 seats in, and control of, the House of Representatives,^[244] "humbling" and a "shellacking".^[245] He said that the results came because not enough Americans had felt the effects of the economic recovery.^[246]

Cultural and political image[link]

Obama conducting the first completely virtual interview from the White House in 2012^[247]

Obama's family history, upbringing, and Ivy League education differ markedly from those of African American politicians who launched their careers in the 1960s through participation in the civil rights movement.^[248] Obama is also not a descendant of American slaves.^[249] Expressing puzzlement over questions about whether he is "black enough", Obama told an August 2007 meeting of the National Association of Black Journalists that "we're still locked in this notion that if you appeal to white folks then there must be something wrong".^[250] Obama acknowledged his youthful image in an October 2007 campaign speech, saying: "I wouldn't be here if, time and again, the torch had not been passed to a new generation."^[251]

Obama is frequently referred to as an exceptional orator.^[252] During his pre-inauguration transition period and continuing into his presidency, Obama has delivered a series of weekly Internet video addresses.^[253]

According to the Gallup Organization, Obama began his presidency with a 68 percent approval rating^[254] before gradually declining for the rest of the year, and eventually bottoming out at 41 percent in August 2010,^[255] a trend similar to Ronald Reagan's and Bill Clinton's first years in office.^[256] He experienced a small poll bounce shortly after the death of Osama bin Laden, which lasted until around June 2011, when his approval numbers dropped back to where they were prior to the operation.^{[257][258][259]} Polls show strong support for Obama in other countries,^[260] and before being elected President he has met with prominent foreign figures including then-British Prime Minister Tony Blair,^[261] Italy's Democratic Party leader and then Mayor of Rome Walter Veltroni,^[262] and French President Nicolas Sarkozy.^[263]

Obama talks with pub-goers as the First Lady draws a pint of stout at the Ollie Hayes pub in Moneygall, Ireland, in 2011

In a February 2009 poll conducted by Harris Interactive for France 24 and the International Herald Tribune, Obama was rated as the most respected world leader, as well as the most powerful.^[264] In a similar poll conducted by Harris in May 2009, Obama was rated as the most popular world leader, as well as the one figure most people would pin their hopes on for pulling the world out of the economic downturn.^[265][266]

Obama won Best Spoken Word Album Grammy Awards for abridged audiobook versions of Dreams from My Father in February 2006 and for The Audacity of Hope in February 2008.^[267] His concession speech after the New Hampshire primary was set to music by independent artists as the music video "Yes We Can", which was viewed 10 million times on YouTube in its first month^[268] and received a Daytime Emmy Award.^[269] In December 2008, Time magazine named Obama as its Person of the Year for his historic candidacy and election, which it described as "the steady march of seemingly impossible accomplishments".^[270]

On October 9, 2009, the Norwegian Nobel Committee announced that Obama had won the 2009 Nobel Peace Prize "for his extraordinary efforts to strengthen international diplomacy and cooperation between peoples".^[271] Obama accepted this award in Oslo, Norway on December 10, 2009, with "deep gratitude and great humility."^[272] The award drew a mixture of praise and criticism from world leaders and media figures.^[273][274] Obama is the fourth U.S. president to be awarded the Nobel Peace Prize and the third to become a Nobel laureate while in office.

Family and personal life[link]

Barack Obama posing in the White House with wife Michelle and daughters Sasha and Malia in 2009

In a 2006 interview, Obama highlighted the diversity of his extended family: "It's like a little mini-United Nations", he said. "I've got relatives who look like Bernie Mac, and I've got relatives who look like Margaret Thatcher."^[275] Obama has a half-sister with whom he was raised, Maya Soetoro-Ng, the daughter of his mother and her Indonesian second husband and seven half-siblings from his Kenyan father's family – six of them living.^[276] Obama's mother was survived by her Kansas-born mother, Madelyn Dunham,^[277] until her death on November 2, 2008,^[278] two days before his election to the Presidency. Obama also has roots in Ireland; he met with his Irish cousins in Moneygall in May 2011.^[279] In Dreams from My Father, Obama ties his mother's family history to possible Native American ancestors and distant relatives of Jefferson Davis, President of the Confederate States of America during the American Civil War.^[280]

Obama was known as "Barry" in his youth, but asked to be addressed with his given name during his college years.^[281] Besides his native English, Obama speaks Indonesian at the conversational level, having learned the language during his four childhood years in Jakarta.^[282] He plays basketball, a sport he participated in as a member of his high school's varsity team.^[283]

Obama taking a shot during a game on the White House basketball court, 2009

Obama is a well known supporter of the Chicago White Sox, and threw out the first pitch at the 2005 ALCS when he was still a senator.^[284] In 2009, he threw out the ceremonial first pitch at the all star game while wearing a White Sox jacket.^[285] He is also primarily a Chicago Bears fan in the NFL, but in his childhood and adolescence was a fan of the Pittsburgh Steelers, and recently rooted for them ahead of their victory in Super Bowl XLIII 12 days after Obama took office as President.^[286] In 2011, Obama invited the 1985 Bears to the White House; in 1986, the team did not attend due to the Space Shuttle Challenger disaster.^[287]

In June 1989, Obama met Michelle Robinson when he was employed as a summer associate at the Chicago law firm of Sidley Austin.^[288] Assigned for three months as Obama's adviser at the firm, Robinson joined him at group social functions, but declined his initial requests to date.^[289] They began dating later that summer, became engaged in 1991, and were married on October 3, 1992.^[290] The couple's first daughter, Malia Ann, was born on July 4, 1998,^[291] followed by a second daughter, Natasha ("Sasha"), on June 10, 2001.^[292] The Obama daughters attended the private University of Chicago Laboratory Schools. When they moved to Washington, D.C., in January 2009, the girls started at the private Sidwell Friends School.^[293] The Obamas have a Portuguese Water Dog named Bo, a gift from Senator Ted Kennedy.^[294]

Applying the proceeds of a book deal, the family moved in 2005 from a Hyde Park, Chicago condominium to a $1.6 million house in neighboring Kenwood, Chicago.^[295] The purchase of an adjacent lot—and sale of part of it to Obama by the wife of developer, campaign donor and friend Tony Rezko—attracted media attention because of Rezko's subsequent indictment and conviction on political corruption charges that were unrelated to Obama.^[296]

In December 2007, Money magazine estimated the Obama family's net worth at $1.3 million.^[297] Their 2009 tax return showed a household income of $5.5 million—up from about $4.2 million in 2007 and $1.6 million in 2005—mostly from sales of his books.^[298][299] On his 2010 income of $1.7 million, he gave 14 percent to non-profit organizations, including $131,000 to Fisher House Foundation, a charity assisting wounded veterans' families, allowing them to reside near where the veteran is receiving medical treatments.^[300][301]

As per the latest financial disclosure, Obama may be worth as much as $10 million.^[302]

Obama tried to quit smoking several times, sometimes using nicotine replacement therapy, and, in early 2010, Michelle Obama said that he had successfully quit smoking.^[303][304]

Religious views[link]

Obama is a Christian whose religious views developed in his adult life. He wrote in The Audacity of Hope that he "was not raised in a religious household". He described his mother, raised by non-religious parents (whom Obama has specified elsewhere as "non-practicing Methodists and Baptists"), to be detached from religion, yet "in many ways the most spiritually awakened person that I have ever known". He described his father as "raised a Muslim", but a "confirmed atheist" by the time his parents met, and his stepfather as "a man who saw religion as not particularly useful". Obama explained how, through working with black churches as a community organizer while in his twenties, he came to understand "the power of the African-American religious tradition to spur social change".^[305]

In an interview with the evangelical periodical Christianity Today, Obama stated: "I am a Christian, and I am a devout Christian. I believe in the redemptive death and resurrection of Jesus Christ. I believe that that faith gives me a path to be cleansed of sin and have eternal life."^[306]

On September 27, 2010, Obama released a statement commenting on his religious views saying "I'm a Christian by choice. My family didn't—frankly, they weren't folks who went to church every week. And my mother was one of the most spiritual people I knew, but she didn't raise me in the church. So I came to my Christian faith later in life, and it was because the precepts of Jesus Christ spoke to me in terms of the kind of life that I would want to lead—being my brothers' and sisters' keeper, treating others as they would treat me."^[307][308]

Obama was baptized at the Trinity United Church of Christ, a black liberation church, in 1988, and was an active member there for two decades.^[309] Obama resigned from Trinity during the Presidential campaign after controversial statements made by Rev. Jeremiah Wright became public.^[310] After a prolonged effort to find a church to attend regularly in Washington, Obama announced in June 2009 that his primary place of worship would be the Evergreen Chapel at Camp David.^[311]

Notes[link]