Evaluate the study by Dement and Kleitman (sleep and dreams) in terms of two strengths and two weaknesses. At least one of your evaluation points must be about generalisations.

Mark scheme

Marking points from the official mark scheme (Oct/Nov 2020). The mark or mark type is shown in brackets.

1. Strengths include: reliability, qualitative data, quantitative data
2. Weaknesses include: ethics, validity (external), generalisability
3. Level 4 (8-10 marks) Evaluation is comprehensive; Answer demonstrates evidence of careful planning, organisation and selection of material; Analysis (valid conclusions that effectively summarise issues and arguments) is evident throughout; Answer demonstrates an excellent understanding of the material.
4. Level 3 (6-7 marks) Evaluation is good; Answer demonstrates some planning and is well organised; Analysis is often evident but may not be consistently applied; Answer demonstrates a good understanding of the material.
5. Level 2 (4-5 marks) Evaluation is mostly appropriate but limited; Answer demonstrates limited organisation or lacks clarity; Analysis is limited; Answer lacks consistent levels of detail and demonstrates a limited understanding of the material.
6. Level 1 (1-3 marks) Evaluation is basic; Answer demonstrates little organisation; There is little or no evidence of analysis; Answer does not demonstrate understanding of the material.
7. Level 0 (0 marks) No response worthy of credit.