Lakha is planning to conduct a study to correlate helpfulness and intelligence. She is going to ask her participants to use an online IQ test and is going to measure helpfulness in the laboratory.

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 suggestion that produces ordinal, interval or ratio data (i.e. that could be correlated)
2. 2nd mark for detail e.g. operationalisation.
3. ∞ using a questionnaire = 1 mark
4. ∞ with questions like 'How likely would you be to assist an old person crossing the street? (on a scale of 0–10) = 2nd mark
5. ∞ by setting up a situation with a stooge = 1 mark
6. ∞ so the participant was asked to help clear up a mess to see how much effort they make (and rate it) = 2nd mark
7. [2] 1 mark for suggested advantage
8. 2nd mark for detail
9. ∞ reliable because objective = 1 mark
10. ∞ e.g. in the questionnaire they could only give a number, so the response does not need to be interpreted = 2nd mark
11. ∞ valid because few demand characteristics = 1 mark
12. ∞ e.g. because with the stooge they would not know helping was part of the study, so they would act normally = 2nd mark
13. Note: These are only examples, there will be many other acceptable answers.
14. [1] 1 mark for scatter graph
15. [1] 1 mark for 'As one variable goes up the other goes down'
16. OWTTE
17. Accept diagram (does not have to be labelled):
18. [2] Both marks for explaining the effect on the correlation.
19. ∞ less helpful participants would score better than they should (so would look like they had higher IQs)
20. ∞ so the negative correlation would look steeper
21. ∞ because the most unhelpful people (the most intelligent ones) would appear (even) more intelligent
22. ∞ it would be less valid, because Lakha would be measuring cheating not IQ