Do you use a Fitbit or another type of technology to track your exercise? Do you find yourself trying to walk more after checking your daily steps? If so, you are taking advantage of reactivity – when people alter their behavior in response to their behavior being measured.
Typically, researchers try their best to avoid reactivity in their studies. If you are interested in observing someone’s natural behavior, you would not want to change it simply by observing it. However, reactivity can occasionally become the subject of research itself, and this is exactly what is happening with a measure used in learning research.