In recent years, statistical data and inference have played an important role in establishing the basic facts used for public policymaking in a variety of areas, such as estimating the unemployment rate, determining the risk of cancer from occupational exposure to toxic chemicals, and the evaluation of the accuracy of screening tests for AIDS antibodies or for drug use. In the legal area, statistical methods are used to examine hiring and promotion data for evidence of discrimination, and also to appraise the fairness of tax assessments. Indeed, methods originally developed for the analysis of medical data have been used to analyze hiring and promotion information -- and the principal investigators of the current project have been active in researching problems arising in this area as well as some of those indicated in the paragraph above. In particular, motivated by the AIDS crisis, the investigators will use funds to be provided under the recommended award to pursue further research into estimators of the prevalence of a disease and the predictive value of screening tests in populations with low prevalence (less than one in one hundred). They plan to adapt confidentiality techniques originally designed for economic data to suggest procedures for obtaining a reliable estimate of AIDS prevalence while still preserving the anonymity of the individuals tested. Under the recommended award the investigators also plan to adapt methods used to evaluate medical screening tests to evaluate an apparent response bias in the Census Bureau's major unemployment survey, and to study other measurement problems requiring the development of statistical procedures which produce valid results even when all the usual assumptions are not satisfied by the data. The research is expected to make contributions to statistical theory in addition to its timeliness in proferring applications to recently recognized problems that are certain to be with us for some years to come.
