PSYCH 100A Lecture Notes - Lecture 9: Analysis Of Variance, Null Hypothesis, Cognitive Behavioral Therapy
Document Summary
The most popular measure of an anova effect size. Proportion of all out variation that can be attributed to our grouping. Or, as we talked about with anova, the proportion of variation that i know comes from my manipulation. I know why this happened/this is all that happened. Think back to the independent samples t-test. We establish the null hypothesis to test if our data are unlikely under the null. We expect the null hypothesis to be true. If we count the two groups equally then their difference, under the null, they should be equal to zero. Comparing one (or more) groups to a different set of one (or more groups) Null: there are no differences between the hippie and placebo. We don"t have mu, so we use xbar. Xbar1 - xbar2/2 - xbar3/2 = 0. We know there is random variability so we need to account for variability when looking at our data.
