A-LevelPsychologyResearch methods9990/21 · May/June 2019 · Q99 Marks

Ella is conducting a laboratory experiment to find out whether singing helps people to relax. She is using a repeated measures design and will use pulse rate to measure relaxation.

(a)Identify a suitable control condition for Ella's experiment.[1]
(b)Explain why a repeated measures design is the best experimental design for Ella's study.[3]
(c)Explain one disadvantage of using a repeated measures design in Ella's study.[2]
(d)Ella considered using a field experiment but decided to use a laboratory experiment. Explain why it could have been better for Ella to conduct a field experiment.[3]

Mark scheme

Marking points from the official mark scheme (May/June 2019). The mark or mark type is shown in brackets.

[1] 1 mark for control condition of 'no singing'
people who don't sing = 1 mark
a group who talk/whistle/hum instead of singing = 1 mark
NB candidates may interpret this as 'listening to singing', accept this interpretation, in which case the appropriate control may be 'silence' or 'listening to music with no lyrics'
[1] 1 mark for idea of individual differences
[1] 2nd mark for linking this to singing
[1] 3rd mark for detail e.g. in relation to the effect on relaxation
people in an independent groups design might vary = 1st mark
people are different = 1st mark
it avoids the effects of individual differences = 1st mark
they might differ in their normal pulse rate = 2nd mark
this would be an uncontrolled variable = 3rd mark
it would reduce the validity of the study = 3rd mark
it could make it look as if there were differences in relaxation when really there were not = 3rd mark
[2] Both marks are for one disadvantage.
At least one point must be linked to the study.
there could be an order effect / a practice effect = generic mark
The participants will have to have their relaxation level measured twice = link mark
the second time they will know how this is done so might be more relaxed anyway = link mark
they are likely to work out the aim of the study/there is a bigger risk of demand characteristics (than with an independent measures design) = generic mark
so might try to relax more the second time = link mark
[1] 1 mark for each reason for being better as a field experiment (max 3)
[1] 2nd and 3rd mark may be for detail (including relevant use of terms)
At least one mark must link directly to the study
More ecologically valid = = 1st mark (generic)
the participants would be less likely to guess the aim/ would not know they were in a study = 1st mark (generic)
so their singing would be natural rather than forced = 2nd mark (link)
there would be less risk of demand characteristics = 2nd mark (generic)
so it would be more valid = 3rd mark (generic)