In an experiment investigating the effect of praise on task persistence, 30 participants were asked to solve a difficult spatial reasoning puzzle. Half of the participants (Condition A) received enthusiastic praise from the researcher after 3 minutes, while the other half (Condition B) received no feedback. The researcher measured how many minutes each participant persisted with the puzzle before giving up.
Different participants were used in each condition of the experiment, which might have affected the results due to individual differences in natural persistence or spatial ability.
Explain one way in which the experiment could be changed to control for the problem of using different participants in each condition.
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.