About the Data
A Technical Guide to Information Resources
Found on this Site

The information about the IRS, its criminal and civil enforcement efforts and the taxpaying behavior of the American people, was compiled by TRAC from a variety of sources. The sources included computerized data obtained under the Freedom of Information Act from the Justice Department, the Internal Revenue Service, and the United States Office of Personnel Management. These data were supplemented by interviews with current and former government officials, tax attorneys, and agency data processing specialists.

Additional information was drawn from internal administrative records, electronic and hardcover publications of the Internal Revenue Service; internal administrative records and statistical reports of the Justice Department; electronic databases, internal records and hardcover publications of the Administrative Office of the United States Courts; internal records and published reports of the Office of Personnel Management; electronic databases of the U.S. Congress; internal records and published reports of the General Accounting Office; and county-level and geo-based files from the United States Census Bureau.

This section on "About the Data" provides information about the following topics. Choose from the following links for further details on each of these topical areas:

• Judging the Quality of Government Data: general information about how to judge the quality of government statistics, and what steps TRAC uses to assess the quality of data it receives.
  
  
• Understanding the Terminology which Agencies Use: specialized terminology used by these agency sources in categorizing their activities.
  
  
• Data Coverage: what the agency's databases were designed to cover and how these activities were recorded.
  
  
• Data Limitations: limitations TRAC uncovered in its analyses of these data sources as to their accuracy and completeness.

One limitation that should be highlighted: The information provided the public by the Internal Revenue Service about the agency's criminal enforcement activities are substantially inaccurate. Taken as a whole, the data provide a highly misleading picture of the enforcement efforts of one of the IRS's most important components, the Office of Criminal Investigation. This finding is noted elsewhere. A special section on IRS Criminal Enforcement Data Systems describes TRAC's findings at some length. Because these data cannot be relied upon to describe the IRS's criminal enforcement efforts, we have not used them for our Web sites.