The primary goal of activity-based models is a fundamental examination of the behavioral process that results in revealed travel behavior. To reveal this process, a new computer program, iCHASE, has been developed to collect data for a study of the determinants of travel and activity behavior in households. This data is inherently dynamic, since respondents record planned activity schedules and then update these schedules, on a daily basis, fully defined in time and space. The resultant data will facilitate the identification of fundamental inter-relationship among a comprehensive range of revealed travel and activity participation variables, leading toward the identification of what are the critical variables, relationships, and rules that govern that behavior. It is believed that an internet-based travel survey, particularly one as rich in resultant content as iCHASE, will significantly reduce data collection costs, improve data quality and quantity, and allow for continuous data collection.