A psychologist investigates whether plate colour affects how much food adults serve themselves. Thirty-six adults take part in a specially prepared dining room. The researcher gives each adult either a red plate or a white plate. The plates are the same size, and every adult serves the same pasta from identical heated containers using the same ladle. An electronic scale on the serving counter records the mass of pasta each adult takes, in grams.
Evaluate the use of a laboratory experiment in this study.
139 exam-style questions on OCR GCSE Psychology 7.2 Doing Research, covering 7.2.1 Experiments, 7.2.2 Interviews, 7.2.3 Questionnaires (Surveys), 7.2.4 Observations, 7.2.5 Case Studies, and 7.2.6 Correlations. Each one has a worked solution and a mark scheme showing where the marks go.