Examiner conclusions, based on chart interpretation alone, are but a single element of all the evidence that is collected in the course of a thorough investigation. Contributing factors to the polygraph accuracy include the examiner, the examinee, the investigation, and the examination conditions. Qualified examiners are well-trained through accredited programs, have received refresher training on a regular basis, have gained professional experience, and exercise their personal integrity in the course of their investigations. Physical, emotional, and psychological conditions affecting the examinees must also be considered when conducting a polygraph test. Because the examiner is dependent upon investigative input as a foundation for the examination, the quality of the investigation is crucial to polygraph accuracy. The examiner needs to know the alleged role of the examinee in the case and any previous statements he has made. Adverse examination conditions, such as poor physical facilities, examiner stress, deviation from standard procedures, or elements of subjectivity can impact on the test's accuracy. A final element useful in assessing polygraph results is a quality control review of the examination, carried out independently to determine whether the examiner's conclusions are substantiated by the charts. 7 endnotes.