As Martinson mentions in his book, “A study had to be an evaluation of a treatment method, it had to employ an independent measure… it had to use some control group, some untreated individuals with whom the treated ones could be compared.” (Martinson 205) The methodology that Martinson approached was analyzing 231 studies that possessed sufficient data to be able to include them in the study. According, to Martinson these treatment studies used various measures of offender improvement. Recidivism rates, adjustment to prison life, vocational success, educational achievement, personality and attitude change, and general adjustment to the outside community. All of these measures were included in his study, but he only focused with the
