Correlation and Regression Revision

What does the correlation coefficient measure?

• The strength of a relationship

• The cause of a relationship

• The direction of a relationship

• The rate of change in a relationship

Which value of the correlation coefficient indicates a perfect positive linear relationship?

• -1

• 0

• 1

• 0.5

If the correlation coefficient between two variables is 0, what does this imply?

• There is a strong positive linear relationship

• There is a strong negative linear relationship

• There is no linear relationship

• The variables are perfectly correlated

What is the range of values for the correlation coefficient?

• -1 to 1

• 0 to 1

• -∞ to ∞

• -2 to 2

A correlation coefficient of -0.8 suggests what kind of relationship?

• Perfectly positive

• Perfectly negative

• Strongly positive

• Strongly negative

Which of the following methods can be used to determine correlation?

• Pearson's r

• Spearman's ρ

• Kendall's τ

• All of the above

What does a correlation coefficient of 0.3 typically indicate?

• Strong positive correlation

• Moderate positive correlation

• Weak positive correlation

• No correlation

The correlation coefficient is least appropriate for which type of relationship?

• Linear

• Curvilinear

• Monotonic

• Nonlinear

Which correlation coefficient is best suited for ordinal data?

• Pearson's r

• Spearman's ρ

• Kendall's τ

• Both B and C

If two variables have a correlation coefficient of 0.9, what can be inferred?

• They have a weak positive relationship

• They have a moderate negative relationship

• They have a strong positive relationship

• They are unrelated