Week Two - One-Way ANOVA & Effect Size

Question 1

Any persons score can be defined as?

Answer 1

Grand mean + treatment effect + residual error

Question 2

How does ANOVA work?

Answer 2

By breaking down all the variation in scores (variance) into two parts: variance due to the effects of treatment and error variance, producing the F stat.

Question 3

Assumptions of ANOVA?

Answer 3

HOMOGENEITY OF VARIANCE.
NORMALITY
INDEPENDENCE OF OBSERVATIONS

Question 4

What do degrees of freedom represent?

Answer 4

The number of independent pieces of data, or values that are free to vary after a mean (or means) have been estimated

Question 5

What is the mean square and how is it obtained?

Answer 5

The MS is the variance and is obtained by dividing the sums of squares for each effect by the corresponding DF

Question 6

What does statistical significance tell us?

Answer 6

Whether an observed difference would have occurred purely by chance or not

Question 7

What does psychological significance tell us?

Answer 7

Whether an observed finding is meaningful; assessed by effect size

Question 8

What does Cohen’s d express?

Answer 8

The difference between means in terms of the size of SD

Question 9

How does Hedge’s g differ from Cohen’s d?

Answer 9

Equivalent but has a corrections factor to account for the bias from small samples

Question 10

What does n squared measure and describe?

Answer 10

It measures the strength of association between the DV and IV and describes the proportion of variance of the DV which may be explained by variation of the IV.