Which of the following refers to the reliability of results across different sample groups?

The concept you are referring to is external validity, which is concerned with the generalizability of research results across different sample groups and settings. External validity assesses whether the findings from a study can be applied to populations beyond the individuals who participated in the research. This means that if a study demonstrates its results are reliable across various groups, it has strong external validity, allowing researchers to feel confident that the outcomes can be expected in a broader context.

For instance, if a social work study involving a specific population demonstrates effective intervention strategies, external validity would support the idea that these strategies could be effective for other populations or in different environments. This is crucial for practitioners who aim to apply findings from research to real-world situations where diverse client groups exist.

In contrast, internal validity focuses on the accuracy of the results within the specified study itself, ensuring that the observed effects are truly due to the manipulated variables and not other factors. Statistical regression refers to a phenomenon in research where extreme scores tend to move closer to the average upon successive measurements—not directly related to sampling across population groups. Single-system design pertains to a methodology used often in social work to evaluate the effectiveness of interventions on a single individual or group, rather than the reliability of findings across sample groups.

Understanding external