The debate on the usefulness of rehabilitation efforts among offender populations has been ongoing since the 1960's. The topic received major exposure through an article by Robert Martinson on the subject in 1974. The article was critical of rehabilitation results in general and the California Community Treatment Program in particular. A reanalysis of the program's results indicated that the number of participant offenses had been substantially undercounted. Supporters argued that the uncounted offenses represented minor or technical evaluations, and the argument continued for several years. Although Martinson may have been right in this instance, it has not been proven that no rehabilitation efforts are successful. In fact, results of analyses of the Community Treatment Program indicated that while some types of offenders - intelligent, verbal, neurotic ones- might be more amenable to treatment, others may actually be reinforced in their criminal activities by treatment. Also, revised methods of measuring recidivism may indicate that treatment is effective. Measures of the incidence of rearrests per individual rather than arrest or parole or probation violation rates have indicated that restrictive supervision of parolees reduced the number of times they were rearrested. It is possible, however, that the subjects became more adept at avoiding arrest, but the decrease in rearrest incidence was such as to indicate that it was the result of treatment rather than criminal learning effect. Footnotes are included.