Caveats on a process-tracing measure and a remedy

In process-tracing studies, a frequently used index describes whether information selection behavior is attribute — or alternativewise. The performance of this index is investigated under the assumption that subjects select information in a random fashion. The results show that the index may lead to inaccurate conclusions regarding the information-acquisition strategy of a subject. In addition, a Monte Carlo study is conducted that examines the sensitivity of the index to strategy changes. An alternative index is derived and a latent-class model is proposed for a parsimonious representation of individual differences in information acquisition.