On the validity of non-randomized response techniques: an experimental comparison of the crosswise model and the triangular model.

Non-randomized response techniques (NRRTs) such as the crosswise model and the triangular model (CWM and TRM; Yu et al. Metrika, 67, 251-263, 2008) have been developed to control for socially desirable responding in surveys on sensitive personal attributes. We present the first study to directly compare the validity of the CWM and TRM and contrast their performance with a conventional direct questioning (DQ) approach. In a paper-pencil survey of 1382 students, we obtained prevalence estimates for two sensitive attributes (xenophobia and rejection of further refugee admissions) and one nonsensitive control attribute with a known prevalence (the first letter of respondents' surnames). Both NRRTs yielded descriptively higher prevalence estimates for the sensitive attributes than DQ; however, only the CWM estimates were significantly higher. We attribute the higher prevalence estimates for the CWM to its response symmetry, which is lacking in the TRM. Only the CWM provides symmetric answer options, meaning that there is no "safe" alternative respondents can choose to distance themselves from being carriers of the sensitive attribute. Prevalence estimates for the nonsensitive control attribute with known prevalence confirmed that neither method suffered from method-specific bias towards over- or underestimation. Exploratory moderator analyses further suggested that the sensitive attributes were perceived as more sensitive among politically left-oriented than among politically right-oriented respondents. Based on our results, we recommend using the CWM over the TRM in future studies on sensitive personal attributes.