An educational psychologist investigated whether wearing blue-light filtering glasses improves proofreading performance compared to wearing standard clear-lens glasses. They conducted a controlled laboratory experiment.
In Condition A (Blue-Light Filter), participants wore blue-light filtering glasses while proofreading a digital text on a tablet for 10 minutes, and the number of undetected errors was recorded.
In Condition B (Standard Clear), the same participants proofread an equivalent digital text for 10 minutes on the same tablet while wearing identical-looking clear-lens glasses with no blue-light filter.
The order in which participants completed the two conditions was counterbalanced across the group.
The psychologist analyzed the results using a Wilcoxon signed-ranks test and found that the number of undetected errors was significantly lower in the Blue-Light Filter condition.
What is meant by a causal explanation? Explain why it was appropriate to claim that there was a causal explanation in this study.
Practise AQA A Level Psychology Experimental method with exam-style questions for A Level Psychology. 32 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.