Question

An educational psychologist is testing the discriminant validity of a new measure of numerical learning difficulties. He gives his measure to a group of students along with another measure of verbal learning difficulties, which he predicts should not be strongly related to numerical learning difficulties. Which of the following correlations would the psychologist hope to find in order to establish discriminant validity?

a.r = 1.0
b.r = 0.83
c.r = −0.18
d.r = −1.0

Answer 1

The educational psychologist would hope to find an r value indicating a weak or no relationship, such as c. r = -0.18, to establish discriminant validity between measures of numerical and verbal learning difficulties.

Step-by-step explanation:

The educational psychologist would hope to find a correlation that is not strong between the new measure of numerical learning difficulties and the measure of verbal learning difficulties to establish discriminant validity. This would suggest that the two measures are indeed capturing different constructs. The correlation coefficient (r) value that indicates a weak or no relationship between the two measures would be ideal.From the given options, the psychologist would hope to find:

c. r = −0.18

This value indicates a very weak negative relationship between the measures, which is what is desirable for discriminant validity. Higher positive or negative correlation values (such as r = 1.0, r = 0.83, or r = −1.0) would suggest a substantial relationship between the measures, contradicting the goal of proving discriminant validity.

Answer 2

The answer is option C. -0.18

Step-by-step explanation:

This is the correct option because: if the r value is closer to 0 it indicates a weak correlation as it is stated in the question. Instead, if the r value is closer to 1 it would indicate a strong correlation.