The purpose of this study was to evaluate how information collected by the Unemployment Insurance Service under the Continuous Wage and Benefit History (CWBH) system can be used to analyze UI recipients? unemployment experiences. The study had both analytical and methodological focuses. With respect to analyzing UI recipients? unemployment experiences, three general issues were investigated in detail: providing detailed description of such unemployment measures as initial unemployment spells, weeks of UI benefits collected, exhaustion rates for both regular and extended UI benefits, post-exhaustion unemployment, and post-unemployment wage rates; developing analytical models to explain and predict these unemployment outcomes using data from the CWBH system; using the data to attempt an evaluation of the services provided to UI recipients by state Employment Services (ES). The study also had major methodological components related both to the overall suitability of the CWBH data set for UI research and to ways in which that data set might be supplemented. Specifically, three questions related to the supplementation of CWBH data were addressed: Is there a need to supplement the CWBH data set to include information on individuals? complete unemployment spells? If the CWBH data set were to be supplemented with additional data on unemployment experiences, what form would that data collection effort take? Can the CWBH data be supplemented with data from the ESARS systems to provide reliable evaluations of services provided through the ES? In the final section of this chapter we provide summary of our results as they relate to each of these analytical and methodological questions.