Dr. Farah is investigating the impact of chronic sleep restriction on salivary cortisol levels, a biological marker of physiological stress. To do this, she recruits a volunteer sample of 12 female undergraduate nursing students, aged 18–22, from her university department.
Explain one improvement that could be made to the sample gathered by Dr. Farah for her study.
82 exam-style questions on Edexcel A Level Psychology Research methods and skills, covering Research methods and skills. Each one has a worked solution and a mark scheme showing where the marks go.