Faculty of Public Health & Policy, London School of Hygiene & Tropical Medicine, London, United Kingdom.
PLoS One. 2012;7(6):e39116. doi: 10.1371/journal.pone.0039116. Epub 2012 Jun 19.
The concept of demand characteristics, which involves research participants being aware of what the researcher is investigating, is well known and widely used within psychology, particularly in laboratory-based studies. Studies of this phenomenon may make a useful contribution to broader consideration of the effects of taking part in research on participant behaviour. This systematic review seeks to summarise data from studies of the effects of demand characteristics on participant behaviours in non-laboratory settings.
METHODOLOGY/PRINCIPAL FINDINGS: Electronic databases were searched to identify eligible studies. These had to be purposely designed to evaluate possible effects of demand characteristics on at least one behavioural outcome under the autonomous control of the participants and use longitudinal study designs. Only 7 studies were included, 6 providing observational data and 1 experimental study, with 5 studies involving examination of possible effects on health behaviours. Although studies provided some evidence of effects of demand characteristics on participant behaviour, heterogeneous operationalisation of the construct, the limited number of studies and poor quality of study designs made synthesis and interpretation of study findings challenging.
CONCLUSIONS/SIGNIFICANCE: Although widely accepted as important in psychology, there have been few dedicated studies of the effects of demand characteristics on research participant behaviours outside laboratory settings. This body of literature does not currently contribute to the wider study of research participation effects. A systematic review of data from laboratory-based studies is needed, as are high-quality primary studies in non-laboratory settings. We suggest that unqualified use of the term demand characteristics should be abandoned.
需求特征的概念，即研究参与者意识到研究人员正在调查什么，在心理学中是众所周知且广泛应用的，尤其是在基于实验室的研究中。对这一现象的研究可能会对更广泛地考虑参与研究对参与者行为的影响做出有用的贡献。本系统评价旨在总结非实验室环境中需求特征对参与者行为影响的研究数据。
方法/主要发现：电子数据库被搜索以确定符合条件的研究。这些研究必须是专门设计的，以评估需求特征对参与者自主控制下的至少一个行为结果的可能影响，并使用纵向研究设计。仅包括 7 项研究，其中 6 项提供观察数据，1 项实验研究，5 项研究涉及对健康行为可能影响的研究。尽管这些研究提供了一些关于需求特征对参与者行为的影响的证据，但由于该结构的操作化异质性、研究数量有限以及研究设计质量差，使得对研究结果的综合和解释具有挑战性。
结论/意义：尽管在心理学中被广泛认为很重要，但在实验室环境之外，很少有专门研究需求特征对研究参与者行为的影响的研究。这一文献体并没有为更广泛的研究参与效果研究做出贡献。需要对基于实验室的研究数据进行系统评价，以及在非实验室环境中进行高质量的初级研究。我们建议放弃使用未经限定的“需求特征”一词。
