Physical Therapy Assistant Practice Exam

Which type of reliability examines the consistency of results over repeated testing by the same individual?

1. Intertester reliability

2. Internal consistency reliability

3. Intratester reliability

4. Split-half reliability

The correct answer is: Intratester reliability

Intratester reliability focuses on the consistency of results obtained by the same examiner on repeated occasions. This type of reliability ensures that the same individual administering a test or evaluation yields similar outcomes when the testing is performed multiple times under the same conditions. It is crucial in clinical settings, where a therapist must assess a patient's progress or response to treatment accurately over time. For example, if a physical therapist measures a patient’s range of motion on separate visits, intratester reliability would assess whether the therapist produces consistent measurements despite the influence of minor variations in technique or the patient's condition. Reliability in this sense is vital for establishing trustworthy progress metrics and ensuring effective treatment plans. In contrast, other types of reliability refer to different aspects of measurement consistency. Intertester reliability examines agreement between different testers, internal consistency reliability assesses whether various items on a test measure the same construct, and split-half reliability evaluates the consistency of results from different halves of a single test. Each serves distinct purposes in research and clinical practice, but for the question posed, intratester reliability is the most appropriate choice.