Certified Rehabilitation Counselor Practice

Which reliability estimate focuses on repeating the same test at separate times?

1. Split half reliability

2. Test retest reliability

3. Parallel forms reliability

4. Cronbach's alpha

The correct answer is: Test retest reliability

Test-retest reliability is a crucial concept that measures the consistency of a test over time. This reliability estimate is achieved by administering the same test to the same group of individuals on two different occasions. The aim is to determine how stable and consistent the test results are across these separate administrations. When the same test is given at two different times, the correlation between the scores from the two testing occasions provides insight into whether the test consistently measures what it is intended to measure. If the results are similar, it indicates high test-retest reliability, suggesting that the test scores are stable. This is particularly important in fields such as rehabilitation counseling, where accurate and consistent assessments are necessary for effective treatment planning and progress monitoring. In contrast, the other estimates mentioned serve different purposes. Split-half reliability assesses the internal consistency of a test by splitting it into two halves and comparing the scores. Parallel forms reliability involves creating different versions of the same test and comparing the results from the different forms, while Cronbach's alpha is a statistic used to measure internal consistency within a single test rather than across different time points. Each of these methods emphasizes different aspects of reliability, making test-retest reliability specifically focused on the temporal stability of test scores.