Reactivity
Also called: reactive effects of measurement
Definition
A change in behavior caused by the act of measuring it, such as a learner behaving better while an observer is visibly recording, or a staff member following the plan more closely during an integrity check. It usually fades with exposure, and it argues for unobtrusive measurement and for observing often enough that observation becomes ordinary.
In plain language
People act differently when they know they are being watched or recorded. The effect usually wears off with time.
Example
A student's off-task behavior drops sharply the day a new observer sits at the back of the room, then returns over the week.
Not reactivity
An observer gradually loosening their scoring standard. That is observer drift.
See also
Written from
- kazdin-1979
Written from Kazdin (1979). No textbook glossary consulted.
This entry has not yet been through clinical review. Treat it as a draft.