- published: 28 Aug 2013
- views: 6161
The power or sensitivity of a binary hypothesis test is the probability that the test correctly rejects the null hypothesis (H0) when the alternative hypothesis (H1) is true. It can be equivalently thought of as the probability of accepting the alternative hypothesis (H1) when it is true—that is, the ability of a test to detect an effect, if the effect actually exists. That is,
The power of a test sometimes, less formally, refers to the probability of rejecting the null when it is not correct, though this is not the formal definition stated above. The power is in general a function of the possible distributions, often determined by a parameter, under the alternative hypothesis. As the power increases, there are decreasing chances of a Type II error (false negative), which are also referred to as the false negative rate (β) since the power is equal to 1−β, again, under the alternative hypothesis. A similar concept is Type I error, also referred to as the “false positive rate” or the level of a test under the null hypothesis.
Definition of power, Type II errors, and sample size issues. More info at my website: http://bit.ly/5fuFsY
This video is the first in a series of videos related to the basics of power analyses. All materials shown in the video, as well as content from the other videos in the power analysis series can be found here: https://osf.io/a4xhr/
If you are at a university other than UCSD and have found this or any of my other videos to be useful, please do me a favor and send me a note at ProfessorParris@gmail.com indicating your university affiliation and which videos you've found useful. Thank you! - Dr. Julian Parris ---- Tutorial on Visualizing and Calculating Statistical Power for simple hypothesis testing using z-tests.
A discussion of Type I errors, Type II errors, their probabilities of occurring (alpha and beta), and the power of a hypothesis test.
There is a mistake at 9.22. Alpha is normally set to 0.05 NOT 0.5. Thank you Victoria for bringing this to my attention. This video reviews key terminology relating to type I and II errors along with examples. Then considerations of Power, Effect Size, Significance and Power Analysis in Quantitative Research are briefly reviewed. http://youstudynursing.com/ Research eBook on Amazon: http://amzn.to/1hB2eBd Check out the links below and SUBSCRIBE for more youtube.com/user/NurseKillam Quantitative research is driven by research questions and hypotheses. For every hypothesis there is an unstated null hypothesis. The null hypothesis does not need to be explicitly stated because it is always the opposite of the hypothesis. In order to demonstrate that a hypothesis is likely true researchers...
How to calculate beta and power. This video attempts to simply explain the concept of statistical power. The first half of the video works with some given information (Ho/Ha, n, sigma, and alpha). At the 8 minute mark, I introduce the alternative mu of 20.5 (a hypothetical value, as are most alternative values of mu, to calculate the power of the test against this alternative). This is a "two sided, greater than" example. A "one sided, less than" example can be found here: http://www.youtube.com/watch?v=zXbSogwX8Wc Stoney Pryor
Goal: Define statistical power and sample size in clinical practice and the USMLE boards Objectives: Identify the factors affecting statistical power Differentiate between type I and II errors Select methods to improve statistical power in research studies Differentiate between sensitivity, specificity, positive predictive value and negative predictive value Understand a receiver operator curve
More Info http://j.mp/2fgfBuD Use Excel 2013’s statistical tools to transform your data into knowledge Conrad Carlberg shows how to use Excel 2013 to perform core statistical tasks every business professional, student, and researcher should master. Using real-world examples, Carlberg helps you choose the right technique for each problem and get the most out of Excel’s statistical features, including recently introduced consistency functions. Along the way, he clarifies confusing statistical terminology and helps you avoid common mistakes. You’ll learn how to use correlation and regression, analyze variance and covariance, and test statistical hypotheses using the normal, binomial, t, and F distributions. To help you make accurate inferences based on samples from a population, this edition ...
Get your free audiobook or ebook: http://yazz.space/sabk/35/en/B01DY7LRM0/info Statistical Power Analysis for the Behavioral Sciences, Revised Edition emphasizes the importance of statistical power analysis. This edition discusses the concepts and types of power analysis, t test for means, significance of a product moment rs, and differences between correlation coefficients. The test that a proportion is .50 and sign test, differences between proportions, and chi-square tests for goodness of fit and contingency tables are also elaborated. This text likewise covers the F tests of variance proportions in multiple regression/correlation analysis and computational procedures. This publication is intended for behavioral and biosocial scientists who use statistical inference, but also serves as ...
This is an introduction to the concept of power in statistics. This is important to help you choose an appropriate sample size. This is part of a lecture series (5 videos) covering several supplemental topics in statistics. The PowerPoint and data sets can be downloaded at: https://www.researchgate.net/profile/David_Dunaetz/publication/308996129_PowerPoint_for_Supplemental_Topics_in_Statistics/links/57fd7a5508ae49db47553c1b If you have not installed the Data Analysis Toolpak (which comes free with Excel), the following video will show you how to do it. Windows: https://www.youtube.com/watch?v=rq8VynGNAFU Mac: https://www.youtube.com/watch?v=1R_aJ_Fli2w
This lecture shows how to calculate the power for Ttest type data using R
This lecture covers how to calculate the power for data which are going to be evaluated with the t-test
Read your free e-book: http://hotaudiobook.com/mebk/50/en/B00GISRRLS/book This is the first book to demonstrate the application of power analysis to the newer more advanced statistical techniques that are increasingly used in the social and behavioral sciences. Both basic and advanced designs are covered. Readers are shown how to apply power analysis to techniques such as hierarchical linear modeling, meta-analysis, and structural equation modeling. Each chapter opens with a review of the statistical procedure and then proceeds to derive the power functions. This is followed by examples that demonstrate how to produce power tables and charts. The book clearly shows how to calculate power by providing open code for every design and procedure in R, Sas, and Spss. Readers can verify the power...
Read your free e-book: http://hotaudiobook.com/mebk/50/en/B007NYFOUC/book Statistical power analysis has revolutionized the ways in which we conduct and evaluate research. Similar developments in the statistical analysis of incomplete (missing) data are gaining more widespread applications. This volume brings statistical power and incomplete data together under a common framework, in a way that is readily accessible to those with only an introductory familiarity with structural equation modeling. It answers many practical questions such as: How missing data affects the statistical power in a study How much power is likely with different amounts and types of missing data How to increase the power of a design in the presence of missing data, and How to identify the most powerful design in th...
2014 Fall Meeting Section: Hydrology Session: Advances in Hydrometeorological Predictions and Applications I Title: Maximizing Statistical Power When Verifying Probabilistic Forecasts of Hydrometeorological Events Authors: DeChant, C M, Civil and Environmental Engineering, Portland State University, Portland, OR, United States Moradkhani, H, Civil and Environmental Engineering, Portland State University, Portland, OR, United States Abstract: http://abstractsearch.agu.org/meetings/2014/FM/H34A-03
Force of Will has had a lot of complaints about Power Creep over it's four block life, but that talk is mostly about effects. That Statistics of the card have Power Crept too. The card I mention as 500/500 but 400/400 normally is The Servant of the Mikage.
Read your free e-book: http://copydl.space/mebk/50/en/B00M6T8R1W/book Noted for its accessible approach, this text applies the latest approaches of power analysis to both null hypothesis and minimum-effect testing using the same basic unified model. Through the use of a few simple procedures and examples, the authors show readers with little expertise in statistical analysis how to obtain the values needed to carry out the power analysis for their research. Illustrations of how these analyses work and how they can be used to choose the appropriate criterion for defining statistically significant outcomes are sprinkled throughout. The book presents a simple and general model for statistical power analysis based on the F statistic and reviews how to determine: the sample size needed to achie...
Statistical Power is a conditional probability of a correct decision given that there truly is an effect. Power is affected by the sample size, the effect size, the alpha, and the variance.
Statistics for the Behavioral Sciences
Statistics for the Behavioral Sciences
An introduction to the multiple comparison problem (i.e. multiple null hypotheses) and how to deal with these using Bonferroni's correction and Tukey's Post-Hoc test. SPSS is also used to run tests multiple times (akin to repeating an experiment) to demonstrate that the p-value itself has a distribution. This is used as the basis for introducing the concept of statistical power.
Dale W. Usner, Ph.D., President at SDC, explains the basics of statistical power for non-statisticians, highlighting what you need to know about statistical power, how it affects your clinical trial, and what to ask for from your statistician.
Using SPSS Sample Power 3, G*Power and web-based calculators to estimate appropriate sample size. G*Power Download site: http:--www.psycho.uni-duesseldorf.de-abteilungen-aap-gpower3-download-and-register Web-Based Calculators: http:--danielsoper.com-statcalc3-default.aspx (scroll down to menu labelled -Sample Size-
Hypothesis Testing, Power, and Sample Size Estimation in Medical Research by Peter Homel, PhD, Department of Pain Medicine and Palliative Care, Beth Israel Medical Center, New York, NY Lecture presented on 12/12/2011