A graphical model is a probabilistic model for which a graph denotes the conditional independence structure between random variables. They are commonly used in probability theory, statistics—particularly Bayesian statistics—and machine learning.

Generally, probabilistic graphical models use a graph-based representation as the foundation for encoding a complete distribution over a multi-dimensional space and a graph that is a compact or factorized representation of a set of independences that hold in the specific distribution. Two branches of graphical representations of distributions are commonly used, namely, Bayesian networks and Markov networks. Both families encompass the properties of factorization and independences, but they differ in the set of independences they can encode and the factorization of the distribution that they induce.

If the network structure of the model is a directed acyclic graph, the model represents a factorization of the joint probability of all random variables. More precisely, if the events are Failed to parse (Missing texvc executable; please see math/README to configure.): X_1,\ldots,X_n

Daphne Koller (born 1968 or 1969) is a Professor in the Department of Computer Science at Stanford University and a MacArthur Fellowship recipient. She's also one of the founders of Coursera, an online education platform. Her general research area is artificial intelligence and its applications in the biomedical sciences. Koller was featured in an article by MIT Technology Review titled "10 Emerging Technologies That Will Change Your World" concerning the topic of Bayesian Machine Learning.

She received a bachelor's degree from the Hebrew University of Jerusalem in 1985 and a Master's degree from the same institution in 1986.

Koller completed her Ph.D. at Stanford in 1993 under the supervision of Joseph Halpern, and joined the faculty of the Stanford University Computer Science Department in 1995. She was named a MacArthur Fellow in 2004.

In April 2008, Daphne Koller was awarded the first-ever $150,000 ACM-Infosys Foundation Award in Computing Sciences.

In 2009 she published a textbook on Probabilistic Graphical Models together with Nir Friedman. She will offer a free online course on the subject starting February 2012.