A psychologist wanted to investigate the effect of sleep duration on cognitive performance. She recruited 20 university students and split them into two groups. Group A slept for 8 hours, while Group B slept for only 4 hours. The next morning, all participants completed a reaction time test (measured in milliseconds).
Write a suitable directional hypothesis for this study.
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.