Physical Therapy Assistant Practice Exam

Which reliability type focuses on the consistency of results across items within a test?

1. Intertester reliability

2. Intratester reliability

3. Internal consistency reliability

4. Reliability of parallel forms

The correct answer is: Internal consistency reliability

Internal consistency reliability is the type that focuses on the consistency of results across items within a test. This concept is crucial in assessing how well various items that are supposed to measure the same construct correlate with one another. High internal consistency suggests that the items are measuring the same underlying attribute, providing confidence that the test is reliable in its measurement. For a practical application, imagine a questionnaire designed to assess pain levels. If multiple questions within the questionnaire consistently yield similar results, it signifies strong internal consistency. This indicates that the items collectively form a cohesive assessment tool, enhancing the overall validity of the evaluation. The other reliability types, while important in their contexts, do not address the consistency of results across the components of a single test. Intertester reliability pertains to the agreement between different assessors, intratester reliability concerns the stability of results when the same tester administers the test multiple times, and parallel forms reliability deals with the consistency of results between different versions of a test. Understanding internal consistency is vital for developing effective assessment tools in physical therapy and ensuring that they yield reliable and valid results.