Study 1
The study by Robinson and colleagues (2011) used an experimental pretest/posttest design to examine the impact of Staff Training Aimed at Reducing Rearrest (STARR). Federal probation officers who volunteered to participate in STARR were randomly assigned to the experimental (trained) and control (untrained) groups. The randomization procedure was completed so that 66 percent of the officers were randomly assigned to the experimental group and the remaining officers were assigned to the control group. Although the officers were randomly assigned to the two study conditions, the clients (people on probation) were not. However, as with most community supervision agencies, client assignment was based on rotation, caseload size, or other factors that were unrelated to officer status in the study.
The total number of officers in the experimental group was 41, and the total number of officers in the control group was 26. Clients were identified for inclusion in the study based on when their period of supervision began. The sample included clients on pretrial supervision and postconviction supervision. Pretraining cases were those cases that either 1) began pretrial supervision during 2007 and 2008 and terminated supervision before the training event date, or 2) began postconviction supervision between May 31, 2007, and May 31, 2008. This allowed for a follow-up time of at least 12 months. Posttraining cases were those that either 1) were assigned to study officers for pretrial supervision after May 31, 2009, or 2) were assigned for postconviction supervision after May 31, 2009, and up until Dec. 12, 2009.
In total, there were 446 pretraining cases and 295 posttraining cases assigned to the experimental officers and 345 pretraining cases and 218 posttraining cases assigned to the control officers. Most of the clients were on postconviction supervision. Clients assigned to the experimental officers were 15 percent female and 57 percent minority, with an average age of 35.0 years. Clients assigned to the control officers were also 15 percent female and 57 percent minority, with an average age of 34.6 years. There were no significant differences between the clients on demographic characteristics.
Audiotape recordings of interactions between the officers and their clients were reviewed to measure the use of skills taught during STARR. In total, 731 audio recordings were submitted for review, which included 491 recordings from the experimental group and 240 from the control group. Trained raters coded the audiotapes and concentrated primarily on behaviors consistent with the skills introduced during the training. The analysis concentrated on three intermediate variables: 1) the officer’s use of reinforcement and disapproval, 2) interactions where cognitions, peers, or coping skills were discussed, and 3) the officer’s use of cognitive techniques during interactions with clients. There were no significant differences between the experimental and control groups in the use of these skills found in the analysis of pretraining audiotapes.
There were two client outcome measures used in the study. For pretrial clients, the outcome measure was failure on supervision, including failure to appear in court, supervision being revoked, or being arrested for a new criminal charge while on pretrial supervision. The data for this measure was collected from PACTS (Probation/Pretrial Services Automated Case Tracking System), an electronic case management tool used by probation and pretrial service officers in all 94 federal districts to track federal defendants and convicted persons. For postconviction clients, the outcome measure was arrest for a new criminal behavior. Data on arrests was collected from the National Crime Information Center and the National Law Enforcement Telecommunications System, which together include data on federal and local charges.
Bivariate analyses were used to assess the change in officer behavior from pretraining to posttraining and across the experiment and control groups. Bivariate analyses were also used to assess the impact of training on client outcomes. Multivariate analyses were used to determine the interaction between individual and client characteristic and officer training, and their impact on client outcomes. Subgroup analysis examined the failure rates of clients by risk level.
Study 2
Lowenkamp and colleagues (2014) used the same sample as in Study 1 by Robinson and colleagues (2011), but extended the follow–up period to look at outcome measures at the 24-month follow up.
The first study (Robinson et al. 2011) included those on pretrial supervision and postconviction supervision. However, due to policies in place with regard to the collection of arrest information, the 2014 follow-up study only included persons on postconviction supervision. The new sample size comprised 999 people; there were 595 in the experimental group and 404 in the control group. The new sample was 14 percent female, 61 percent minority (no other race/ethnicity information was provided), and the average age was 35 years. A little over half of the sample (52 percent) was considered high risk, and the other half (48 percent) was considered moderate risk. There were no statistically significant differences between the groups on baseline characteristics. The study sample included 26 officers in the trained group (experimental group) and 15 officers in the untrained group (control group).
The outcome of interest was failure rates, which was measured as arrests for a new criminal behavior. The differences between the groups was examined using chi-square test statistics that account for the time period supervised (pre- and posttraining) and group assignment (control and experimental group officers). Subgroup analysis examined the failure rates of clients by risk level.
