Identification of Falsifications in Survey Data

• Applicants: Professorin Dr. Natalja Menold; Professor Dr. Peter Winker
• Subject Area: Empirical Social Research
• Term: from 2012 to 2016
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 218596777

Building on the first phase of the project, we extend our analysis in three aspects. First, the case of partial falsifications is taken into account, i.e. that interviewers falsify only some interviews and/or only parts of interviews. It is analyzed to what extent the existent methods are still useful in this setting. Second, the study of interviewers’ motivation is extended taking into account also theories of motivation from psychology. Based on this theoretical background, hypothesis about the type and extent of partial falsifications are derived. We will use an experiment to test these hypotheses and to derive further indicators focusing on partial falsifications. Third, in the presence of partial falsifications, the use of deterministic clustering methods does not appear adequate. Instead, probabilistic clustering methods are considered which allow describing the data for one interviewer as a mixture of two distributions. To overcome numerical problems of these methods, optimization heuristics are used. Furthermore, the modelling approach is extended to more than two clusters, allowing for different types of falsifications depending on factors such as motivation or experience. All results are used to improve questionnaires and survey methodology in order to deter falsifications by enhancing interviewers’ motivation and increasing the chance of ex post detection.

• DFG Programme: Research Grants
• Participating Person: Dr. Christoph Kemper