Anova

Anova

اسلاید 1: ANOVAArash Mashhadi

اسلاید 2: Why ANOVA?In real life things do not typically result in two groups being comparedTest lines on I-64 in FrankfortTwo-sample t-tests are problematic Increasing the risk of a Type I errorAt .05 level of significance, with 100 comparisons, 5 will show a difference when none exists (experimentwise error)So the more t-tests you run, the greater the risk of a type I error (rejecting the null when there is no difference)ANOVA allows us to see if there are differences between means with an OMNIBUS test

اسلاید 3: When ANOVA?Data must be experimentalIf you do not have access to statistical software, an ANOVA can be computed by hand With many experimental designs, the sample sizes must be equal for the various factor level combinationsA regression analysis will accomplish the same goal as an ANOVA. ANOVA formulas change from one experimental design to another

اسلاید 4: Variance – why do scores vary?A representation of the spread of scoresWhat contributes to differences in scores?Individual differencesWhich group you are i