A school questionnaire asks, "How many minutes of vigorous exercise did you do yesterday?" and "Describe anything that made exercise difficult."
Outline two problems of using a questionnaire in 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.