Explain one participant variable that Dr. Vance could have controlled for when planning her structured, non-participant observation of senior citizens using a new self-service supermarket terminal.
Practise Edexcel A Level Psychology Methods with exam-style questions for A Level Psychology. 100 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.