A psychologist wants to investigate the sleep habits of sixth-form students at one college. She numbers every sixth-form student on the college's sixth-form register and uses a random number generator to select 40 of them. Explain one strength and one limitation of the sampling method used in this investigation.
182 exam-style questions on OCR GCSE Psychology 7.1 Planning Research, covering 7.1.1 Hypotheses, 7.1.2 Variables, 7.1.3 Experimental Designs, 7.1.4 Populations and Sampling, 7.1.5 Ethical issues, and 7.1.6 Dealing with ethical issues and BPS Code. Each one has a worked solution and a mark scheme showing where the marks go.