Identification and Diagnosis of Misreporting in Surveys

Misreporting and other forms of aberrant responding can undermine the validity of survey-based inferences. Person-level evaluation of aberrant responses is rarely conducted because inspecting individual response patterns is time-intensive. This study proposes an integrated approach for identifying, classifying, and interpreting misfitting response patterns using nonparametric visualizations of person response functions combined with clustering of person response functions. The first step is to calibrate the survey items using an IRT model, such as the Rasch model, to establish an interpretable latent continuum with item-location ordering. Next, person-fit statistics, such as infit and outfit mean square error statistics, are examined, and a smaller subset of response patterns is flagged as misfitting. The third step is to use a nonparametric Hanning procedure to create person response functions, followed by clustering misfitting person response functions using Partitioning Around Medoids (PAM). The advantage of PAM over other clustering methods is that an observed response pattern is identified as a representative case for each cluster. Clusters can then be identified that correspond to an appropriate interpretation for the cluster, such as underreporting, inconsistent reporting, and overreporting patterns. Finally, decisions can be made about how to address aberrant person response patterns. The Household Food Security Survey Module from the U.S. Census is used as an illustration. These visualizations can support transparent data-quality evaluation with the potential for survey improvements.