The double-edged sword of rewards for participation in psychology experiments.

Abstract

This quasi-experimental study examined participation rates and sample characteristics of participants recruited with and without the offer of course credit. In Sample 1, where course credit is not usually offered, credit was added in one condition (N =195) and not in the other (N = 175). In Sample 2, where credit is usually offered, it was maintained in one condition (N = 92) and removed in the other (N = 178). Results in both samples revealed that participation rates were higher in the credit conditions; they plunged when customary rewards were taken away. Results also revealed evidence of sample bias. More specifically, the motivational characteristics of participants and nonparticipants differed in all conditions except the new credit condition.

Bank Directors’ Perceptions of Expanded Auditor's Reports

“…Above all, the participants were not paid. Rewards lead to more participation (Patel, Doku & Tennakoon, ), should attract those who are motivated by more extrinsic reasons, and thus provide a sample that is more representative regarding motivational characteristics (Sharp, Pelletier & Lévesque, ), and may enhance subject motivation and performance (Cameron, Bank & Pierce, ). By contrast, some researchers argue that incentives generally make no difference (Camerer & Hogarth, ) or even that the negative effects of rewards are pervasive (Deci, Pierce & Ryan, ), because they may destroy intrinsic motivation (Pierce et al , ).…”

What brings your subjects to the lab? A field experiment

“…MacDonald (1972) finds that subjects are more likely to volunteer to participate for course credit than for money or "for love of science". Also Sharp et al (2006) conclude that extra credits result in higher sign-up rates. Studies also find that participants self-select to experiments with different descriptions, depending i.a.…”

The impact of MeSH (Medical Subject Headings) terms on information seeking effectiveness

“…We were concerned that difficult tasks may prevent participants from completing all searches, and that the motivational characteristics of participants are possible sources of sample bias (Sharp, Pelletier & Levesque, 2006). The experimental setting for most searchers was a university office; for some searchers, it was a medical library.…”

“…Considering the relatively difficult tasks, searchers may have problems completing all searches. And because research literature has suggested that the motivational characteristics of participants are possible sources of sample bias (Sharp, Pelletier & Levesque, 2006), we designed an incentive system to motivate the searchers.…”