10. Correlation interpretations

Question 1

What five factors affect the size of the correlation? (Methods1 correlation interpretation)

Answer 1

• Sample size
• Linearity
• Variability
• Homoscedasticity
• Discontinuous distributions

Question 2

How does sample size affect the size of the correlation? (Methods1 correlation interpretation)

Answer 2

The larger the sample, the more stable the correlation coefficient

Question 3

How does linearity affect the size of the correlation? (Methods1 correlation interpretation)

Answer 3

r is misleading if there is a strong but non-linear correlation

Question 4

How does variability affect the size of the correlation? (Methods1 correlation interpretation)

Answer 4

The smaller the variability, the lower the apparent correlation

Question 5

How does homoscedasticity affect the size of the correlation? (Methods1 correlation interpretation)

Answer 5

r describes the average strength of the relationship between X and Y

Question 6

How does discontinuous distributions affect the size of the correlation? (Methods1 correlation interpretation)

Answer 6

Few outliers distort the r considerably

Question 7

What is a moderate correlation due to? (Methods1 correlation interpretation)

Answer 7

• Sampling variation

- Genuine association

Question 8

What is statistical significance? (Methods1 correlation interpretation)

Answer 8

How likely it is to obtain a correlation of a given size, purely by chance, if there was no other relationship between the 2 parent populations

Question 9

What is practical importance? (Methods1 correlation interpretation)

Answer 9

R2 is the measure of effect size