This is when we look at the effect on behavior when the independent variable (intervention) is present or absent.
Real-life example: After seeing a psychologist, you decide that Lexapro is in your near future. Constantly moody and feeling a bit on edge, this magic pill can supposedly take the edge off and make you feel alive again. For a straight month, you take your Lexapro religiously. Following this month and seeing an increase in your positive vibes, you decide to go #coldturkey on the Lexapro and completely stop taking it. The purpose in doing so would be to determine if you actually need it to maintain those positive vibes, baby.
Clinical Example: The clinical team decides to implement Greg Hanley’s “My Way” Protocol for 2 consecutive weeks. Following the client meeting a pre-set mastery criteria (i.e., using functional communication independently for 5 consecutive sessions), the team is instructed to remove the intervention and collect baseline data without the use of the intervention.