What does external validity refer to in a scientific study?

External validity refers to the extent to which the results of a scientific study can be generalized beyond the specific conditions or sample used in the study. This concept emphasizes how applicable the findings are to real-world settings, populations, or other contexts outside of the controlled environment of the study. For instance, if a study demonstrates that a particular dietary intervention is effective for weight loss in a specific group of individuals, external validity assesses whether similar results would likely occur among different populations or in real-life situations.

In contrast, the other options focus on elements that do not directly address generalizability. The accuracy of measurements pertains to how well the data represents what it is intended to measure, while internal consistency relates to the reliability of the measures within the study itself. Lastly, the specific conditions under which the study was conducted are more concerned with the study's internal environment rather than how its findings can be applied elsewhere. Thus, understanding external validity is crucial for evaluating how useful the results of a study might be in broader applications.