Treatment Drift
Also called: procedural drift
Definition
A gradual departure from the written procedure as an intervention continues, so that what is being delivered later differs from what was delivered at the start, often without anyone deciding to change it. It is a threat to internal validity and is detected by ongoing treatment-integrity measurement.
In plain language
The plan slowly stops being followed exactly, a little at a time, without anyone deciding to change it. Regular integrity checks catch it.
Example
Over a month, prompts that were supposed to be delayed five seconds start coming almost immediately.
Not treatment drift
The supervisor formally revising the prompt delay and updating the plan. That is a planned change, not drift.
See also
Written from
- peterson-homer-wonderlich-1982
Written from Peterson, Homer and Wonderlich (1982). No textbook glossary consulted.
This entry has not yet been through clinical review. Treat it as a draft.