Introduction to Power Analysis | StatsExamples

pleiotropy
pleiotropy
2.3 هزار بار بازدید - 3 سال پیش - This video introduces the concept
This video introduces the concept of power analysis, calculating our probability of not rejecting a false null hypothesis. The relationship between type I and type II errors, alpha and beta, and statistical power is covered.

The symbol beta is described and power is defined as 1-beta. Power is increased when the pattern of difference is larger, the variance is smaller, the sample size is larger, and when we use parametric tests instead of nonparametric tests.

Two-sample homoscedastic t-tests are used to illustrate the effects of differences in the population means, variance, and sample sizes on the power of this test. Approximations for the relative power of the Mann-Whitney U test and the Wilcoxon signed rank test are shown.

Post-hoc power analysis is also discussed in terms of calculating what we could have observed given the power of a test we performed.

This is the video that answers the question: what is power analysis?

StatsExamples website:
http://www.statsexamples.com/
Link to a related video about type I and type II errors is here:
Type I and type II errors | StatsExam...
Link to a related video about false positives and negatives is here:
False positives and negatives | Stats...


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3 سال پیش در تاریخ 1400/01/30 منتشر شده است.
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