A history instructor has given the same pretest and the same

A history instructor has given the same pretest and the same final examination each semester. She is interested in determining if there is a relationship between the scores of the two tests. She computes the linear correlation coefficient and reports it as 1.14. What does this tell the instructor?

Solution

Linear correlation coefficient is a rate of measure of relationship between two variables

It must lie always between -1 and +1.

0 indicates no correlation at all and -1 indicates fully negative correlation and +1 perfectly positive linear correlation.

Hence the instructor calculation is wrong as r cannot exceed 1.

First she must check her calculations and formula used then come to decision whether strong or weak, positive or negative or no correlation