The study by Piliavin et al. (subway Samaritans) raised ethical issues of 'right to withdraw' and 'deception'. Explain why the study by Piliavin et al. raised these ethical issues. right to withdraw deception

Mark scheme

Marking points from the official mark scheme (May/June 2021). The mark or mark type is shown in brackets.

1. [2] Right to withdraw: participants can leave a study at any time (and remove their data) / should not be pressurised to continue (if they don't want to); Piliavin et al.'s participants could not withdraw as they did not know there were observers in the subway carriage / believed the victim/drunk/cane/ill man was real; Participants couldn't leave the train/carriage/subway because they didn't know they were in a study;
2. [2] Deception: participants should not be (deliberately) misinformed / lied to / given false information; Piliavin et al.'s participants were deceived about the role of the stooges/victim/drunk/cane/ill man; The participants didn't know the victims / drunk and ill men weren't real;