For years, the U.S. Bureau of the Census has collected and disseminated data. It has come to realize the importance of these data products for research, analysis, planning, and policy-making. Technological advances of the 1980s have greatly increased the demand for data, particularly for the microdata products. Users now demand more detailed microdata sets than ever before. Unfortunately, the more information which the Census Bureau provides, the greater the risk that a user can determine the responses for some respondents.