Nothing but the truth? Effects of faking on the validity of the crosswise model.

Adrian Hoffmann,Jochen Musch,Julia Meisters,Paolo Roma

doi:10.1371/journal.pone.0258603

Abstract

In self-reports, socially desirable responding threatens the validity of prevalence estimates for sensitive personal attitudes and behaviors. Indirect questioning techniques such as the crosswise model attempt to control for the influence of social desirability bias. The crosswise model has repeatedly been found to provide more valid prevalence estimates than direct questions. We investigated whether crosswise model estimates are also less susceptible to deliberate faking than direct questions. To this end, we investigated the effect of “fake good” instructions on responses to direct and crosswise model questions. In a sample of 1,946 university students, 12-month prevalence estimates for a sensitive road traffic behavior were higher and thus presumably more valid in the crosswise model than in a direct question. Moreover, “fake good” instructions severely impaired the validity of the direct questioning estimates, whereas the crosswise model estimates were unaffected by deliberate faking. Participants also reported higher levels of perceived confidentiality and a lower perceived ease of faking in the crosswise model compared to direct questions. Our results corroborate previous studies finding the crosswise model to be an effective tool for counteracting the detrimental effects of positive self-presentation in surveys on sensitive issues.

Highlights

When questioned about sensitive personal attributes, some individuals tend to answer in line with social norms rather than truthfully
“fake good” instructions resulted in substantially lower prevalence estimates than “honest” instructions in the direct questions (DQ) condition, but not in the crosswise model (CWM) condition
In the DQ condition, less than half as many participants admitted to the sensitive behavior when instructed to “fake good” than when instructed to respond “honestly”, indicating that deliberate faking led to severe underestimation

Summary

Introduction

When questioned about sensitive personal attributes, some individuals tend to answer in line with social norms rather than truthfully. To overcome social desirability bias, indirect questioning formats such as randomized response techniques [RRT; 5] have been proposed. RRTs grant full confidentiality to respondents by adding random noise to their answers. Based on the outcome of a randomization procedure (e.g., the roll of a die), participants are instructed to respond to either statement A with probability p (e.g., “Respond to statement A if you rolled 1 or 2”; p = 2/6), or to statement B with probability 1-p (e.g., “Respond to statement B if you rolled any other number”; 1-p = 4/6). As the randomization outcome remains unknown to the experimenter, neither a “true” nor a “false” response reveals the respondent to be a carrier of the sensitive attribute.

Methods

Results

Discussion

Conclusion