Which of the following factors can strongly impact external validity based on demographic differences?

The concept of external validity refers to the extent to which the findings of a study can be generalized to settings, people, and times beyond the specific conditions of the study itself. When considering how demographic differences impact external validity, within-group differences are particularly salient.

Within-group differences relate to the variations in characteristics, experiences, or responses among individuals who belong to the same demographic group. For example, if a study on a specific intervention involves participants from a diverse community, variations in socioeconomic status, cultural background, or personal experiences within that demographic group can influence how the intervention is received and its effectiveness. If these within-group differences are not adequately addressed or controlled for, it can lead to a misrepresentation of the study's findings when generalized to the entire population with similar demographics.

Therefore, recognizing and accounting for within-group differences enhances the ability to generalize results across diverse populations, thereby strengthening external validity. This understanding is crucial for social workers who aim to ensure that their interventions and programs are effective for a broad audience, thus maximizing the relevance and applicability of research findings to real-world contexts.