What does the term 'external validity' or 'generalizability' refer to in research?

The term 'external validity' or 'generalizability' refers specifically to the ability to apply the findings of a research study beyond the sample used in the study itself. When researchers conduct a study, they often work with a specific group of individuals, and the results they obtain are typically based on that group's characteristics and behaviors. External validity concerns whether those results can be extrapolated to a larger population or to different settings, contexts, or times.

For example, if a study on the effectiveness of a new teaching method is conducted with a group of students in one state, external validity assesses whether the results of that study would hold true for students in other states, or for students in different educational settings. High external validity suggests that the findings are more broadly applicable, while low external validity indicates that the results may only be relevant to the specific sample studied.

This concept is crucial for researchers and practitioners because it helps determine the usefulness and relevance of research findings in real-world applications.