2: Core Concepts

Question 1

What does the sum of squared deviations convey?

Answer 1

Overall variability.

Question 2

What does the mean squared deviation convey?

Answer 2

Variance.

Question 3

n is key to which type of variance?

Answer 3

Population/descriptive.

Question 4

df is key to which type of variance?

Answer 4

Sample/inferential.

Question 5

The more two variable co-vary, the (smaller/larger) the cross-products.

Answer 5

Larger.

Question 6

What is the result of multiplying deviation scores together?

Answer 6

Cross-products.

Question 7

What shows the overall association of deviation scores?

Answer 7

Sum of products.

Question 8

What is correlation in terms of z-scores?

Answer 8

The covariance of the z-scores.

Question 9

Give 3 aspects of correlation that help answer ‘is it real?’

Answer 9

Internal consistency, test-retest reliability and inter-rater reliability.

Question 10

Give 3 aspects of correlation that help answer ‘is it important?’

Answer 10

R squared, eta squared and beta parameters.

Question 11

Give 3 aspects of correlation that help answer ‘do we know what it means?’

Answer 11

Construct validity, convergent and discriminate validity and predictive/criterion validity.

Question 12

What is a key thing to remember for calculating the intercept?

Answer 12

A regression line must pass through the means both variables.