Lecture 8B: Partial Correlation

Question 1

What is a partial correlation?

Answer 1

The correlation of X and Y with Z ‘held constant’ or removed.

Denoted as rxy.z.

Question 2

What does a third factor (Z) do in a partial correlation?

Answer 2

Confounding variable that influences the relationship between variables of interest (X and Y).

Z may be correlated with both X and Y.

Question 3

What is a confounding variable in “To examine the relationship between knee
extensor muscle strength and hip bone density in elderly”?

Answer 3

Body weight (kg)

Body weight was correlated with both knee extensor strength and hip bone density.

Question 4

Fill in the blank: The correlation of X and Y with Z ‘held constant’ is called _______.

Answer 4

[partial correlation].