Explain why low validity would be a problem in experiments.

Mark scheme

Marking points from the official mark scheme (Oct/Nov 2018). The mark or mark type is shown in brackets.

1. [2] 1 mark for saying why low validity is a problem
2. 1 mark for linking to experiments.
3. Note: these two points may be combined for 2 marks
4. Validity is being sure you are investigating what you intended to;
5. Validity is testing or measuring what you claim to test or measure = 1 mark
6. If the study is valid your results are more credible = 1 mark
7. Which means you can believe your findings = 1 mark
8. So the results would be more useful = 1 mark
9. You would not be able to draw a causal conclusion = 1 mark
10. You would not be able to generalise your findings beyond the experimental situation = 1 mark
11. You would not know whether the IV (or extraneous variables) were the cause of changes in the DV = 2 marks
12. Validity means being accurate = 0