Topic 5: Variability

Question 1

What are the four ways to test credibility of your outcome?

Answer 1

Hypothesis testing
Effect size and power
replication
r-squared

Question 2

What is r-squared?

Answer 2

Proportion of variability accounted for

Question 3

Why is hypothesis testing not enough for credibility?

Answer 3

Does not tell you how strongly manipulation of IV is related to change in DV

Question 4

What is SSt?

Answer 4

Total variability

Question 5

What is SSr?

Answer 5

Explained variability

Question 6

What is SSe?

Answer 6

Unexplained variability

Question 7

What is the formula for r-squared with SS-es?

Answer 7

SSr/SSt = r-squared

Question 8

What is r?

Answer 8

A measure of the size of the association between two variables

Question 9

What is 1 - r-squared?

Answer 9

Unexplained variability (SSe)

Question 10

What box is r-squared in a dependent samples design in SPSS?

Answer 10

Paired samples - correlation box

Question 11

What can be used to find r-squared in an independent samples design?

Answer 11

t(obs) and df

Question 12

What is considered a small, medium and large r-squared?

Answer 12

.10, .25, .40

Question 13

What is considered a small, medium and large R-squared?

Answer 13

Small: .01
Medium: .06
Large: .14