these violations do not indicate that such users pose a threat to the community (Petersilia and Turner, 1985; Clear and Terry, 2000).

Also problematic from the standpoint of measurement is the use of rearrests and parole discharge as outcome indicators. Because so few episodes of drug use end in an arrest or parole revocation, it is doubtful that counts of study subjects rearrested or deemed parole violators accurately represent all incidents of relapse to drug use in the 3-year post-prison period. (The outcome measures and elements of the study design used in the Wexler et al., 1992 evaluation of Stay’n Out are summarized in Table E.1.)

Apart from the problem with the use of questionable outcome measures, certain of these analyses raise questions about the oft-cited link between longer retention in treatment and more positive outcomes. Prison treatment staff recommend that participants in the prison therapeutic community remain in treatment for 9–12 months to complete each phase of therapy. And, as expected, those who stayed 9–12 months and com-