Ch. 12: T-Tests for Dependent Samples

How do you find the effect size of a dependent sample?

ES= meanD/sdD Use same guidelines to interpret effect sizes

What is the difference between independent and dependent samples?

Independent samples -two different groups -between subjects effects Dependent samples -same group of participants tested more than once -repeated-measures design -within-subjects effects

What is another name for Dependent samples t-test?

Paired samples t-test

What are the pros and cons of dependent samples?

Pros -need fewer participants to get to the same degrees of freedom/power -each participant serves as his/her own control Cons -order/learning effects -can't always have same person do both things -may increase potential for alternative explanations

How do you find the degrees of freedom for a dependent samples t-test?

n-1 n= numbers of pairs (sample size)

What do the different components of the formula for t in the dependent samples t-test mean?

∑D: sum of all differences between groups of scores ∑D²: sum of column of squared differences (∑D)²: sum of difference column, squared n: number of PAIRS of observations