The report was financed through an LEAA grant and completed at the University of Minnesota. The first chapter describes the history of the lie detector and of the search for physiological components of lying. It concludes that no pattern of physiological response is unique to lying. The second chapter provides background information on examining the reliability and validity of lie detector tests. In the eight chapters that follow, various testing techniques are described and evaluated. These include the clinical lie test, in which the examiner considers the polygraph data together with observations of behavior symptoms and knowledge of case facts and arrives at a clinical diagnosis; the relevant/irrelevant test, in which questions relevant to an investigation are mixed with irrelevant questions that are also nonstressful; and the lie control test, in which lies are elicited and these responses are compared with responses to relevant questions. Other techniques include the truth control test, in which responses to questions about fictitious crimes that resemble the crime under investigation help reveal suspects' apprehensiveness; the positive control test, in which relevant questions serve as their own controls as the subjects are asked to respond both truthfully and falsely to each; and the searching peak-of-tension test, in which subjects' levels of tension are measured as they respond to a series of related questions -- one is assumed to be closest to the truth. The chapters also cover the relevant control screening test, which is most often used to investigate new employees, and the guilty knowledge test, which appears to be the most promising of those tests which are considered. Sample test questions and data tables are included, and related studies are reviewed.