As the Temporary Assistance for Needy Families (TANF) block grant has been implemented by the states, the Congress has asked questions about a broad range of issues concerning welfare reform's consequences. This report examines: (1) the type of data that will be available from national surveys and studies of welfare reform to help assess progress towards TANF's goals, and (2) the usefulness of the data for assessing TANF's progress nationwide. The major objective was to examine data already collected by national surveys of low-income families and for major studies of welfare reform to identify data available for use in a comprehensive assessment of TANF for the reauth. debate. Ill.