Personality Characteristics of Volunteers for Psychological Studies

Abstract

The problem of volunteer bias is seen in terms of the unrepresentativeness or atypicality of the subjects who participate in psychological studies. Findings from investigations of the personality characteristics of volunteers are examined under the headings of: (i) unconventionality, (ii) adjustment, (iii) anxiety, (iv) social extraversion, and (v) need achievement. The percentage volunteering response in the invitation situation may be raised or lowered by incentive or restraint factors. The mean percentage volunteering response in the studies reviewed was 37 per cent. Though studies relating volunteer characteristics specifically to particular distortions in experimental data are few, emphasis has frequently been placed on the potential danger of bias from volunteer subjects. A distinction may possibly be made between volunteering as an expressed willingness to participate, and volunteering as actual participation in the experimental situation. Most volunteer bias studies have, in fact, centred on expressed‐willingness volunteering. It is not yet possible to provide adequate experimental controls based on the prediction of direction and magnitude of sources of volunteer bias in specific laboratory studies.

Sleep and wakefulness in 509 normal human adults

“…Questionnaires and interviews usually leave this to the respondent. A second objection is that volunteer subjects were used and these may be atypical (Bell, 1962), thus bringing bias into the recorded data. A third point is that the data were recorded in the late spring, when the amount of daylight per day was lengthening.…”

The subject matter of psychology: Volunteers

“…Rosenthal & Rosnow's (1975) comprehensive examination leaves little doubt that, although there is not complete agreement on the issue of 'volunteer bias' in relation to a wide range of personality and biographical variables, the problem is a very important one. An earlier review by Bell (1962) also alerted researchers to the matter.…”

Evaluating Newly‐Married Couples

“…The first concern was to make up a true sample of some identifiable sub-population within the community so that we could be fairly sure that our sample would include a wide range of possible marriages. T o this end, therefore, we did not rely on volunteers, since the difficulties of so doing are by now well known (Bell, 1962).…”