Accurately modeling the life-course through panel survey interviewing can be enhanced by making gains in the quality, of retrospective reports in wave-to-wave and intake interviews, and by applying these gains to supplement intake and core wave-to-wave interviews with the collection of new lifetime variables. An Event History Calendar (EHC) questionnaire methodology has considerable potential toward improving the quality of retrospective reports in comparison to standardized question-list (Q-list) methods. As a methodological study, this proposed project will test the quality of social health, and economic retrospective reports provided by both EHC and Q-list methods. Panel surveys would also benefit by collecting information on very early conditions. As a substantive study, this proposed project will collect information on intrauterine conditions and those of very early childhood and model their association with adult chronic conditions, with appropriate controls for health conditions and socioeconomic status as experienced during later childhood and adulthood. Specifically, this proposal will seek to 1) Modify two computer assisted interviewing EHCS, one with a 2-year reference period, and one with a lifetime reference period that both measure key social, health, and economic events. 2) Measure the quality of retrospective reports from EHC and Q-list methods for a lifetime reference period and assess the impact of the face-to-face mode in comparison to telephone mode with a short-term reference period EHC. 3) Examine the survey cost implications of EHC and Q-list interviewing methods through measures of interviewing time and interviewer and respondent burden. 4) Assess the ability of 2-year retrospective reports on health care utilization that are collected by EHC methods to provide annual estimates of health care costs. 5) Test the ability of EHC and Q-list methods to supplement existing, panel data with high quality lifetime retrospective reports during intake interviews on new variables that have not been collected during core interviewing. Seek to strengthen causal inferences on the relationship between early and later life conditions. 6) Draw implications from the findings in using EHC interviewing methods in future panel waves, supplemental panel data collection, and intake panel surveys. The project is designed to incorporate three phases corresponding to pretesting, data collection, and analytic activities. The first phase will modify existing 2-year and lifetime retrospective CAT-EHCS. Data collection activities will consist of a pilot test of the two-year EHC, and a validation test of lifetime reports provided by EHC and Q-list interviewing methods. During the last year, analytic techniques will be applied to the data to assess the degree to which any EHC improvements to data quality and completeness extend the life-course inferences that can be drawn from panel survey data.