Experimental bias

class=skin-invert-image|thumb|upright=1.3|Whereas a mediator is a factor in the causal chain (above), a confounder is a spurious factor incorrectly implying causation (bottom)

selection of individuals, groups or data for analysis such that proper randomization is not achieved

bias in which a sample is collected in such a way that some members of the intended population are less likely to be included than others

response bias exhibited by survey respondents

type of statistical bias

a general term for a wide range of tendencies for survey participants to respond inaccurately or falsely to questions

form of detection bias

category of response bias common to survey research in which respondents have a tendency to select a positive response option or indicate a positive connotation disproportionately more frequently

extraneous variable in social research