In response to a growing need for effective and efficient means for auditing computer-based systems, a number of studies dealing primarily with batch-processing type computer operations have been conducted to explore the impact of computers on auditing activities in the Federal Government. This report first presents some statistical data on computers in the Federal Government, and then summarizes the results of the studies in three sections. The first section covers those studies dealing with internal auditing of computer-based systems and attempts to determine whether effective independent reviews and appraisals are being made. The next section covers system documentation to determine whether current and complete documentation is maintained; the final section examines the use of computer techniques to audit computer-based systems to assist other Government auditing organizations in checking computer-based systems. Extensive appendices provide more detailed information on auditing procedures. (Author/SH)