The behavioral assessment scale used to measure depressive symptoms had high ecological validity.
However, validity was still a concern because the clinical psychologist conducting the post-treatment evaluations knew whether each participant was in the active cognitive therapy group or the waiting-list control group.
Explain how this could have affected the validity of the study.
689 exam-style questions on AQA A Level Psychology Scientific processes. Each one has a worked solution and a mark scheme showing where the marks go.