A threat to internal validity that refers to any outside event not part of the manipulation that could be responsible for the results is called?

A threat to internal validity that refers to any outside event not part of the manipulation that could be responsible for the results is called?

• A. History effects
• B. Maturation
• C. Attrition
• D. Instrumentation

Answer: (A)

History effects describe outside events that occur during a study and could influence the outcome, even though they’re not part of the manipulation. Because these events come from the real world and affect participants or measurements, they can create changes in the dependent variable that look like the effect of the intervention when they’re actually due to something else. For example, if a new policy or major news event happens while you’re running the study, participants’ performance might improve or worsen because of that event rather than the treatment itself. Maturation would involve natural changes in participants over time, not external events. Attrition refers to participants dropping out, which can bias results if the dropouts are not random. Instrumentation is about changes in measurement tools or procedures. So the scenario described best fits history effects.

History effects describe outside events that occur during a study and could influence the outcome, even though they’re not part of the manipulation. Because these events come from the real world and affect participants or measurements, they can create changes in the dependent variable that look like the effect of the intervention when they’re actually due to something else. For example, if a new policy or major news event happens while you’re running the study, participants’ performance might improve or worsen because of that event rather than the treatment itself.

Maturation would involve natural changes in participants over time, not external events. Attrition refers to participants dropping out, which can bias results if the dropouts are not random. Instrumentation is about changes in measurement tools or procedures. So the scenario described best fits history effects.