Only after an experiment is completed are the research subjects told what the purpose of the experiment is.
When they are it is called.

Question

Quizplus · Accepted Answer

The process described is most commonly called debriefing. It is important to inform research subjects of the purpose of the experiment after it is completed to ensure that they understand why the experiment was conducted and to address any potential concerns or questions they may have. Clarifying, an exit interview, and making a deposition may all be related to research, but they do not specifically address the process of informing research subjects of the purpose of the experiment.

Only After an Experiment Is Completed Are the Research Subjects