In the study by Piliavin et al. (Subway Samaritan), data was collected by two female observers sitting in the adjacent area.
Explain one strength of using two observers to gather data in this study.
105 exam-style questions on OCR A Level Psychology Responses to people in need, covering Piliavin et al. (1969): Subway Samaritan and Levine et al. (2001): Cross-cultural altruism. Each one has a worked solution and a mark scheme showing where the marks go.