A-LevelPsychologyResearch methods9990/23 · Oct/Nov 2018 · Q77 Marks

Mikko is conducting an experiment to find out whether people are more easily persuaded by advertisements that are in colour or in black and white. He has put advertisements up in one town library that are all in colour and the same advertisements in black and white in a library in another town.

(a)Explain the importance of one control in Mikko's experiment.[3]
(b)Suggest how Mikko could operationalise the dependent variable in his experiment.[2]
(c)Explain whether Mikko's study is a field experiment or a natural experiment.[2]

Mark scheme

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

[3] 1 mark for identifying the control
2 marks for explaining why it is important (one may be generic, one must be linked)
same location (= 1 mark for the control)
always a library (= 1 mark for the control)
this might matter because in different locations the type of people might be different (1st explanation mark, generic)
for example in an art shop people might prefer more coloured pictures (2nd explanation mark, linked)
same adverts (= 1 mark for the control)
adverts only differ in terms of colour (not content) (= 1 mark for the control)
this might matter because in different images might affect people differently (1st explanation mark, generic)
for example people might prefer adverts with animals to buildings (2nd explanation mark, linked)
[2] 1 mark for identifying way to operationalise.
1 mark for elaboration / justification e.g. how it would be quantified.
effectiveness of adverts could be operationalised as how much they like them;
e.g. by rating the advert on a scale of 0–10;
effectiveness of adverts could be operationalised by whether they choose the objects advertised;
e.g. by giving them a choice of free products and counting how many they choose;
[2] 1 mark for defining / describing a field experiment or a natural experiment
1 mark for identifying why Mikko's study is a field experiment or is not a natural experiment
a field experiment has a manipulated IV (= 1 mark definition)
a field experiment tests participants in the normal environment (for the behaviour being studied) (= 1 mark definition)
it is a field experiment because people would expect to see adverts in a library (= 2nd mark linked)
in a natural experiment the IV is not manipulated by the researcher / exists in the environment (= 1 mark definition)
it is not a natural experiment because the type of advert is being changed by Mikko (= 2nd mark linked)