A researcher investigates the impact of tidy working spaces on productivity. Participants are placed in an exceptionally clean, minimalist office containing a prominent sign that reads 'Tidy Spaces, Focused Minds'. The participants work significantly faster than those in a control room, with many admitting afterwards that they figured out what the study was testing and wanted to help the researcher get the expected results.
Which of the following terms best describes the threat to validity demonstrated in this scenario?
Investigator effects
Demand characteristics
Social desirability bias
Halo effect
644 exam-style questions on OCR A Level Psychology Research methods and techniques. Each one has a worked solution and a mark scheme showing where the marks go.