Lecture 18

Question 1

What does correlation study rely on?

Answer 1

Relies on associations between variables that already exist

Question 2

How many variables will correlation include?

Answer 2

Only 2

Question 3

What does the Pearson r numerator represent?

Answer 3

Variation in scores associated with apparent linear relationship

Question 4

What does the Pearson r demoninator represent?

Answer 4

Variation associated with apparent linear relationship + variation in scores associated with everyone else

Question 5

What is range restriction?

Answer 5

How much room each variable has to vary

Question 6

If the range is restricted what effect can this have?

Answer 6

It can produce an artificially LOW correlation coefficient

Question 7

What are the negatives of correlation study?

Answer 7

• Difficult to confirm actual direction of possible cause/effect
• Impossible to know from data whether relationship is direct or indirect effect