Methodological considerations in participant event monitoring of low-base-rate events in health psychology: children's injuries as a model.

The present article outlines the advantages of the participant event monitoring methodology for the investigation of unpredictable, low-base-rate events in children. Several methods for assessing the quality of participant event monitoring data are advanced with a data set showing participant event monitoring of children's minor injuries by 61 children and their mothers. Child-mother correspondence and debriefing data suggest good accuracy for frequency estimates. Home- and laboratory-based simulations illustrate the participant event monitors' accuracy for major details. Traditional measures of data quality show good overall coder and test-retest reliability, and cross-observer reports show acceptable estimates of validity for objective aspects of the events and the expected lower estimates for the more subjective aspects. Conceptual and pragmatic difficulties of the method are considered, and suggestions for future research are advanced.