In response to the mandatory Department of Energy (DOE) polygraph testing in October 1999, the National Academy of Sciences (NAS) reviewed the evidence regarding the validity and reliability of the polygraph when used for personnel security screening. Completing the study in October 2002, the NAS concluded that while polygraph testing is more effective when used in connection with event-specific investigations, its accuracy is insufficient to justify reliance on its use in screening current and prospective Federal agency employees -- DOE’s principal purpose in using the polygraph. In populations such as DOE's, where there is an extremely low level of major security violations, the polygraph has serious limitations for use in security screening to identify security risks. It was also reported that there is a realistic possibility that the polygraph might be defeated with countermeasures. Although acknowledging the NAS findings, DOE will continue to use the polygraph for screening purposes, citing it as an effective component of DOE’s counterintelligence program. DOE does not use the polygraph on a stand-alone basis but as part of a larger fabric of investigative and analytical reviews to help security personnel determine if someone is suitable to access to classified data. Polygraphs have value in deterring unauthorized disclosures of classified information. Some members of Congress have called on the DOE to review this decision, and have expressed a desire for a more focused polygraph program that would subject fewer DOE employees to testing. Some of the possible approaches Congress might assess are the retention of the status quo, the establishment of a more focused polygraph program under which those occupying only the most sensitive positions would be polygraphed, more research into alternatives to the polygraph, and the elimination of the polygraph for screening purposes altogether. 55 endnotes