To assess the reliability of a measure, one should _____ the measure.

A) directly observe the amount of true score in
B) manipulate the amount of measurement error in
C) systematically study the variables of
D) calculate the correlation coefficient of the scores of

One way to assess reliability is to calculate the correlation coefficient of the scores of the measure. This coefficient indicates the degree of association between two sets of scores in which the first set is obtained from the measure at one time and the second set is obtained from the measure at a later time. A high correlation coefficient suggests that the measure is reliable.