| ||Literature Coverage Dates||Number of Studies||Number of Study Participants|
|Meta-Analysis 1||1996 - 1999||10||2320|
|Meta-Analysis 2||1996 - 2001||17||5773|
Aos and colleagues (2001) evaluated the costs and benefits of certain juvenile and adult criminal justice policies, violence prevention programs, and other efforts to decrease various at-risk behaviors of youth. The authors used meta-analytic techniques to estimate the degree to which a program or policy can be expected to influence the outcome of interest (i.e. criminality).
The review focused on evaluations that measured a program’s effect on criminal behavior. Program evaluations were gathered from a wide variety of sources, including studies published in peer-reviewed journals as well as government and private agency reports. Once evaluations that met the criteria of inclusion were located, four types of information on the program’s effectiveness in reducing crime were recorded: (1) Did the program affect the percent of the population that offended or reoffend? (2) Of those that offended or reoffended, did the program change the average number of offenses? (3) Did the program affect the types of offenses of those that offended or reoffended? (4) Of those that offended or reoffended, did the program change the timing of offenses? Of the four effects, almost all of the evaluations provided information on the first effect. Far fewer evaluations reported information on the second effect, and even fewer reported information on the third effect. Almost none of the evaluations reported information on the fourth effect.
The search resulted in the inclusion of ten evaluation studies of juvenile boot camp programs. The ten studies included approximately 2,320 study participants, with an average age of 15 years. The studies included published and unpublished evaluations that spanned from 1996 to 1999. No information was provided on the gender and racial/ethnic breakdown of the studies’ samples. The studies were located in various parts of the United States, including Cleveland, Ohio; Denver, Colorado; Mobile, Alabama; Tallahassee, Florida; Clearwater, Florida; Bartow, Florida; Panama City, Florida; California; and Texas.
The mean difference effect size was calculated for each program. Adjustments were made to the effect sizes to account for small sample sizes, evaluations of “non-real world” programs, and for the quality of the research design (the quality of each study was rated using the University of Maryland’s five-point scale; only studies that received a rating of ‘3’ or higher on the scale were included in the analysis). Once effect sizes were calculated for each program effect, the individual measures were added together to produce a weighted average effect size for a program or practice area. The inverse variance weight was calculated for each program effect and those weights were used to compute the average. The fixed effects model was used for the analysis.Meta-Analysis 2
Wilson, MacKenzie, and Mitchell (2008) analyzed results from 32 unique research studies comparing recidivism for participants enrolled in a correctional boot camp program versus some type of comparison condition. Three of the studies reported results from multiple treatment-comparison contrasts. As a result, the 32 studies produced 43 independent samples for analysis. Of the 43 independent samples, 26 included adult boot camp participants and 17 included juvenile boot camp participants. The focus of the results reported here are on the 17 independent samples of juvenile boot camps participants.
A comprehensive search was used to locate eligible studies. Studies were eligible if (1) they evaluated a correctional boot camp, shock incarceration, or intensive incarceration program (i.e. a residential program for convicted offenders that incorporates a militaristic environment and/or structured strenuous physical activity other than work); (2) they included a comparison group that received either probation or incarceration in an alternative facility (one-group research designs were not eligible); (3) study participants were exclusively under the supervision of the criminal or juvenile justice system (i.e. convicted of or adjudicated for an offense); and (4) they reported a post-program measure of criminal behavior, such as arrest or conviction. The comprehensive literature search is current through February 2008.
Of the 32 research studies located during the search process, 22 studies were government reports, eight were found in peer-reviewed journals, and two were available as unpublished technical reports. The 17 independent samples included a total of over 5,000 juvenile study participants. No information was provided on the racial/ethnic and gender breakdown of the studies’ samples. (Most of the student participants were males; only two studies examined the effects of female-only boot camps and seven evaluated mixed gender boot camps). The studies were located in various parts of the United States, including Denver, Colorado; Mobile, Alabama; Cleveland, Ohio; California; and various counties throughout Florida (Bay, Leon, Manatee, Martin, Pinellas, and Polk).
The primary outcome of interest for the meta-analysis was recidivism or a return to criminal activity on the part of the offender after leaving the program (i.e. post-release arrest, conviction, or reinstitutionalization). The analysis looked at nonviolent/nonperson crimes, mixed crimes (violent and nonviolent), and total crimes. Because recidivism data is usually reported dichotomously (whether an offender did or did not reoffend), the index of effectiveness used in the review was the odds-ratio. The odds-ratio is an index of the failure (or success) of one condition relative to another. An odds-ration of 1 indicates that both conditions had equal odds of failure. The independent treatment-comparison samples were the unit-of-analysis for the review. The mean odds-ratio across studies was computed using the inverse variance weight method and a random effects model was assumed.