A cognitive psychologist investigated the effectiveness of a new mnemonic visualization technique ("Method of Loci") on foreign language vocabulary acquisition using two separate groups of adult learners:
Afterwards, the researcher calculated the mean number of words correctly recalled (out of 30) for each group, as shown in Table 1.
Table 1: Mean vocabulary recall scores (out of 30) for Group 1 and Group 2
| Group 1 (Mnemonic training) | Group 2 (Rest control) |
|---|---|
| 23.8 | 15.4 |
The researcher concluded that the mnemonic training may not have been the sole cause of the difference in mean recall scores between Group 1 and Group 2. The researcher was concerned that individual differences in baseline memory capacity and linguistic ability among the participants in the two groups confounded the results.
Explain one way the researcher could change the experimental design to deal with this issue.
Practise AQA A Level Psychology Scientific processes with exam-style questions for A Level Psychology. 689 questions, matched to the AQA A Level Psychology (7182) specification and written in Paper 1, Paper 2 and Paper 3 style. Every question includes a full worked solution and mark scheme, so you can see where marks are awarded rather than just whether you got the answer right.
