MCQ 3

Question 1

Which of the following statements about Pearson’s correlation coefficient is not true?
1. It can only be used with continuous variables
2. It can be used as an effect size measure
3. It varies between –1 and +1
4. A correlation coefficient of zero indicates there is no relationship between the variables

Answer 1

It can only be used with continuous variables

Question 2

The correlation between two variables A and B is .12 with a significance of p < .01. What can we conclude?

1. That there is a substantial relationship between A and B
2. That variable A causes variable B
3. That there is a small relationship between A and B
4. All of these

Answer 2

That there is a small relationship between A and B

Question 3

A Pearson’s correlation coefficient of –.5 would be represented by a scatterplot in which:
1. There is a moderately good fit between the regression line and the individual data points on the scatterplot
2. Half of the data points sit perfectly on the line
3. The regression line slopes upwards
4. The data cloud looks like a circle and the regression line is flat

Answer 3

There is a moderately good fit between the regression line and the individual data points on the scatterplot

Question 4

If two variables are significantly correlated, with r = .67, then:
1. The variables are independent
2. There is no unique variance
3. The relationship is weak
4. They share variance

Answer 4

They share variance

Question 5

The coefficient of determination:
1. Is the square root of the variance
2. Is a measure of the amount of variability in one variable that is shared by the other
3. Is the square root of the correlation coefficient
4. Indicates whether the correlation coefficient is significant

Answer 5

Is a measure of the amount of variability in one variable that is shared by the other

Question 6

A Pearson’s correlation of –.71 was found between number of hours spent at work and energy levels in a sample of 300 participants. Which of the following conclusions can be drawn from this finding?

1. Spending more time at work caused participants to have less energy
2. Amount of time spent at work accounted for 71% of the variance in energy levels
3. There was a strong negative relationship between the number of hours spent at work and energy levels
4. The estimate of the correlation will be imprecise

Answer 6

There was a strong negative relationship between the number of hours spent at work and energy levels

Question 7

If we calculated an effect size and found it was r = .21 which expression would best describe the size of effect?
1. Small
2. Small to medium
3. Medium to large
4. Large

Answer 7

Small to medium