Reliability of the Rasch Food Safety Practices scale

A reduced version of the Rasch Food Safety Practices scale [Fischer, A. R. H., Frewer, L. J., & Nauta, M. J. (2006). Towards improving food safety in the domestic environment: a multi-item Rasch scale for the measurement of the safety efficacy of domestic food handling practices. Risk Analysis, 26(5), 1323–1338] was investigated to establish its reliability and robustness. A second set of survey data were collected using the reduced Rasch scale. We discuss the reliability and robustness of the original Rasch scale in terms of the second analysis. In general, the results of the reduced scale provided results that were very similar to those obtained in the original study. In both studies the goodness of fit of the different items was stable. The range of the difficulty parameters was smaller in this study than in the previous one, which may be attributed to methodological causes. The high level of similarity of the key parameters shows that the Rasch scale is reliable and robust.