prong for two reasons: the scientific literature does not regard the test as a valid diagnostic tool, and "a vast majority of incest offenders who do not admit their guilt, such as Powers, show a normal reaction to the test. The Government argues that such false negatives render the test unreliable." According to Barker and Howell, penile plethysmography (PPG) does not meet the legal threshold for the guilt phase for the following reasons: No standardization Test results are not sufficiently accurate Results are subject to faking and voluntary control by test subjects High incidence of false negatives and false positives Results are open to interpretation They concluded, "Until a way can be devised to detect and/or control false negatives and false positives, the validity of the test data will be questionable." Responding to Barker and Howell, Simon and Schouten noted, "Our own analysis suggests that the standardization and faking issues, as well as other problems not addressed in the Barker and Howell paper, warrant much more guarded conclusions about the use of the plethysmograph in legal and clinical settings." Prentky noted "the increased likelihood in forensic settings that dissimulation may compromise the validity of the assessment." Hall and Crowther noted penile plethysmography "may be even more problematic than other [methods] in assessing susceptibility of the test to faking." In State of North Carolina v. Spencer, the court reviewed the literature and case law and concluded that penile plethysmography was scientifically unreliable: "Despite the sophistication of the current equipment technology, a question remains whether the information emitted is a valid and reliable means of assessing sexual preference." More recently, a substantial amount of research data has been gathered and reviewed, and significant steps have been taken toward standardization. According to Launay (1999), "[T]he validity of the technique for research and clinical assessment is now established;" it is only the use in guilt-determination proceedings that is inappropriate. Fedoroff and Moran called it an "experimental procedure" and noted, "Virtually every expert who has written about phallometry has cautioned that it is insufficiently sensitive or specific to be used to determine the guilt or innocence of a person accused of a sex crime." Post-conviction use Phallometry is widely considered appropriate for treatment and supervision of convicted sex offenders: "Courts have permitted plethysmographic testing for monitoring compliance by convicted sex offenders with the conditions of their community placement as part of crime-related treatment for sexual deviancy." Its use for the treatment and management of sexual offenders is recommended by the Association for the Treatment of Sexual Abusers. Becker notes it "should never be used exclusively in forensic decision making." The sexual assault trial of basketball player Kobe Bryant in Colorado brought this device and its use to public attention before the case was dropped in 2004, because Colorado law would have required evaluation with this device following conviction. The United States Court of Appeals for the Ninth Circuit recently addressed the procedures required before a federal supervised release program could include penile plethysmograph testing. The device is routinely used at civil commitment facilities, but "some clinicians and offenders say it is easy, particularly in a laboratory, to stifle arousal and thus cheat on a plethysmograph test." This has been reported to occur in 16% of cases. During the Catholic sex abuse cases, the reliability of the test was questioned by some officials in the Roman Catholic Archdiocese of Philadelphia. Later, these officials chose to seek therapy at an institution where the plethysmograph was not used. Canada Courts in Canada came to a similar conclusion as those in the United States. The Supreme Court of Canada