A researcher administers a test to 50 subjects and then re-administers the same test on five occasions to the same subjects. Which characteristic of the test is being evaluated?

A researcher administers a test to 50 subjects and then re-administers the same test on five occasions to the same subjects. Which characteristic of the test is being evaluated?

• A. Internal Validity
• B. External Validity
• C. Reliability
• D. Design

Answer: (C)

The main idea here is how consistently a test measures something over time. Administering the same test to the same people on multiple occasions and looking for similar scores is checking the test’s reliability, specifically its test-retest reliability or temporal stability. If the results stay stable across the five administrations, the instrument is considered reliable because it yields consistent measurements for the same individuals. This is distinct from validity, which asks whether the test actually measures the intended trait, and from design or generalizability concerns associated with internal or external validity. So, high consistency across repeated tests indicates strong reliability.

The main idea here is how consistently a test measures something over time. Administering the same test to the same people on multiple occasions and looking for similar scores is checking the test’s reliability, specifically its test-retest reliability or temporal stability. If the results stay stable across the five administrations, the instrument is considered reliable because it yields consistent measurements for the same individuals. This is distinct from validity, which asks whether the test actually measures the intended trait, and from design or generalizability concerns associated with internal or external validity. So, high consistency across repeated tests indicates strong reliability.