Participation bias

Participation bias or non-response bias is a phenomenon in which the results of <a href="/facts/Research/mo8joeTL">studies</a>, <a href="/facts/Opinion_poll/59PEtq3t">polls</a>, etc. become non-representative because the participants disproportionately possess certain traits which affect the outcome. These traits mean the sample is systematically different from the target population, potentially resulting in biased estimates.
For instance, a study found that those who refused to answer a survey on <a href="/facts/AIDS/RqLIEMuJ">AIDS</a> tended to be "older, attend church more often, are less likely to believe in the confidentiality of surveys, and have lower sexual self disclosure." It may occur due to several factors as outlined in <a href="/facts/W._Edwards_Deming/ytaxg6sv">Deming</a> (1990).
Non-response bias can be a problem in <a href="/facts/Longitudinal_study/snyWEsXK">longitudinal research</a> due to <a href="/facts/Attrition_bias/XmeLAXBF">attrition</a> during the study.

Participation bias open-in-new

Participation bias