Background information indicates the Department of Defense has used the polygraph effectively for almost 50 years. It is used primarily in criminal investigations, counterintelligence cases, foreign intelligence and counterintelligence operations, exculpation requests, and counterintelligence-scope screening. The counterintelligence-scope polygraph examination questions focus on whether the examinee has ever engaged in espionage or sabotage, has ever given or sold classified material to unauthorized persons or has been approached to do so, has ever had any unauthorized contact with a representative of a foreign government, or has ever had knowledge of anyone who had been involved in such activities. This report provides information on the number of persons who refused to take a requested polygraph examination and the number of examinations that required more than two series or more than 1 day. Information on polygraph examination results provides statistics on the results of the tests given to 17,970 individuals tested under the Counterintelligence-Scope Polygraph Program. Statistics encompass the number unable to complete the examination, the number whose results were inconclusive, the number that were nondeceptive, the number who made admissions relevant to the issues being tested, and the number assessed as deceptive. The research described addresses that conducted by the Department of Defense Polygraph Institute, which has three congressionally mandated research areas: evaluation of the validity of polygraph techniques, polygraph countermeasures, and developmental research to improve polygraph technology. Appended examples of how the polygraph was used in fiscal year 1993