A health psychologist designs a new questionnaire to measure occupational stress in junior doctors. To evaluate whether the questionnaire produces consistent scores over time, they administer it to a group of 45 junior doctors on a Monday, and then administer the identical questionnaire to the same group two weeks later under identical conditions. They then calculate the correlation coefficient between the two sets of scores.
Which type of reliability is the psychologist directly assessing?
Inter-observer reliability
Test-retest reliability
Split-half reliability
Concurrent validity
