Subject effects in laboratory research: An examination of subject roles, demand characteristics, and valid inference

Stephen J. Weber*, Thomas D. Cook

*Corresponding author for this work

Research output: Contribution to journalArticle

184 Scopus citations


Presents 4 conceptualizations of the role that Ss adopt in laboratory experiments, and assesses empirical support for each. There is no unconfounded evidence that Ss adopt a good S role and seek to confirm hypotheses or that they adopt a negativistic role and seek to sabotage experiments. There is some evidence that in specific contexts Ss may adopt a faithful S role, and there is considerable evidence that Ss are apprehensive about how their performance will be evaluated. Furthermore, providing S with a hypothesis about a study consistently produces bias. These relationships are then examined with respect to their implications for improving research in general and for drawing valid inferences from experimental data. (69 ref.) (PsycINFO Database Record (c) 2006 APA, all rights reserved).

Original languageEnglish (US)
Pages (from-to)273-295
Number of pages23
JournalPsychological Bulletin
Issue number4
StatePublished - Apr 1 1972


  • S effect in laboratory research, good & negativistic & faithful & apprehensive roles & knowledge of hypothesis, implications for drawing valid inferences

ASJC Scopus subject areas

  • Psychology(all)

Cite this