In a study of concentration, 15 participants spend 20 minutes completing wordsearches while sitting in silence. Straight afterwards, the same participants spend another 20 minutes completing wordsearches while a radio plays.
Explain one weakness of the experimental design used in this study.
182 exam-style questions on OCR GCSE Psychology 7.1 Planning Research, covering 7.1.1 Hypotheses, 7.1.2 Variables, 7.1.3 Experimental Designs, 7.1.4 Populations and Sampling, 7.1.5 Ethical issues, and 7.1.6 Dealing with ethical issues and BPS Code. Each one has a worked solution and a mark scheme showing where the marks go.