In a study into the effectiveness of a new herbal patch for reducing physiological stress, researchers provided one group of participants with the active herbal patch and another group with an identical-looking placebo patch.
The researchers were concerned that the outcome of the study might be influenced by the problems of demand characteristics and investigator effects.
Explain what the researchers could do to eliminate or reduce demand characteristics and investigator effects in this 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.