An occupational psychologist, Dr. Mercer, wants to investigate whether inhaling peppermint essential oil can enhance reaction times among assembly line operators during afternoon shifts. She plans to diffuse the oil throughout the assembly area.
Explain two ways that Dr. Mercer could make sure her investigation is scientific.
Practise Edexcel A Level Psychology Methods with exam-style questions for A Level Psychology. 638 questions, matched to the Edexcel A Level Psychology (9PS0) specification and written in Paper 1, Paper 2 and Paper 3 style. Every question includes a full worked solution and mark scheme, so you can see where marks are awarded rather than just whether you got the answer right.