A psychologist wants to find out whether the amount of sleep teenagers usually get is related to their exam results.
Explain two strengths of using a correlation for this investigation.
145 exam-style questions on Oxford AQA IGCSE Psychology 1.4 Research Methods, covering 1.4.1 Hypotheses, 1.4.2 Types of variables, 1.4.3 Sampling methods, 1.4.4 Strengths and weaknesses of sampling methods, 1.4.5 The experimental method, 1.4.6 Experimental designs, 1.4.7 Laboratory experiments, 1.4.8 Field and natural experiments, 1.4.9 Interviews, 1.4.10 Questionnaires, 1.4.11 Case studies, 1.4.12 Observation studies, 1.4.13 Strengths and weaknesses of research methods, 1.4.14 Correlation and scatter diagrams, 1.4.15 Strengths and weaknesses of correlations, 1.4.16 Controlling extraneous variables, 1.4.17 Planning research: reliability and validity, 1.4.18 Ethical issues in research, and 1.4.19 Dealing with ethical issues. Each one has a worked solution and a mark scheme showing where the marks go.