External validity refers to the generalizability of study findings to other settings, populations, or times.

• A. External validity
• B. Internal validity
• C. Face validity
• D. Construct validity

Answer: (A)

Generalizability across settings, populations, and times is what external validity is about. It asks whether findings from a study would apply beyond the exact sample and conditions in which the study was conducted. For example, a treatment that works in a urban hospital with specific patient characteristics might not have the same effect in rural clinics, in different age groups, or years later when practices have evolved. This focus on applying results to other contexts is what distinguishes external validity from another key idea: internal validity, which is about ensuring the observed effect is caused by the intervention within the study itself rather than by biases or confounding factors. Face validity concerns whether a measure appears to assess what it should, and construct validity concerns whether the measurement truly reflects the theoretical concept of interest. Because the statement centers on generalizability to other settings, populations, or times, it matches external validity.