In a study of social cognition, a psychology student investigated children's moral development using a group of 7-year-old children. Each child was shown two short video clips.
The student asked the children to rate how friendly the children in the clips were on a scale of 1–5.
The student decided to test for a significant difference between the friendliness ratings of the two videos. She proposed using a Wilcoxon signed-ranks test to analyse the data.
The student who carried out the study selected the two video clips. She decided herself which video showed cooperative behaviour and which video showed competitive behaviour.
Explain how the study could be improved by selecting the video clips another way.
689 exam-style questions on AQA A Level Psychology Scientific processes. Each one has a worked solution and a mark scheme showing where the marks go.