Log data from educational assessments attract more and more attention and largescale assessment programs have started providing log data as scientific use files. Such data generated as a by-product of computer-assisted data collection has been known as paradata in survey research. In this paper, we integrate log data from educational assessments into a taxonomy of paradata. To provide a generic framework for the analysis of log data, finite state machines are suggested. Beyond its computational value, the specific benefit of using finite state machines is achieved by separating platform-specific log events from the definition of indicators by states. Specifically, states represent filtered log data given a theoretical process model, and therefore, encode the information of log files selectively. The approach is empirically illustrated using log data of the context questionnaires of the Programme for International Student Assessment (PISA). We extracted item-level response time components from questionnaire items that were administered as item batteries with multiple questions on one screen and related them to the item responses. Finally, the taxonomy and the finite state machine approach are discussed with respect to the definition of complete log data, the verification of log data and the reproducibility of log data analyses.