When a change in the dependent variable could be due to the participant's expectation that change will occur, __________ is a threat to internal validity.
A)diffusion of treatments
B)instrumentation
C)placebo effect
D)demand characteristics

Question

Quizplus · Accepted Answer

The placebo effect occurs when participants experience a change in dependent variable due to their expectation that change will occur, even if they did not receive an active treatment. This can be a threat to internal validity as it can make it difficult to determine if the treatment itself caused the change in the dependent variable.

When a Change in the Dependent Variable Could Be Due