Study 1
Rojek, Coverdill, and Fors (2003) used a quasi-experimental design to examine the effectiveness of the Clarke County Victim Impact Panels (VIPs) on rearrest for driving under the influence (DUI). Due to significant variation across counties in content and implementation, only Clarke County, where the program was carefully scripted and controlled, was examined. Starting in 1994, all persons convicted of DUI offenses in Clarke County were required to attend VIP sessions. However, county judges in Clarke County would not allow random selection into treatment groups because it would deny treatment to comparison group members. Therefore, researchers developed a comparison group out of people convicted of DUI from the previous year in the same county.
The treatment group was 404 individuals who were convicted of a DUI offense in the first 6 months of 1994. The comparison group was 430 people convicted of a DUI offense in the first 6 months of 1993. By creating the comparison group in this manner, these individuals had the same judges and the same fines imposed but did not attend the VIP sessions of the treatment group. The treatment group was 82 percent male, and 77 percent white and 23 percent Black. With regards to age, 44 percent were 16–25, 32 percent were 26–35, 19 percent were 36–50, and 6 percent were older than 50. The comparison group was 84 percent male, and 69 percent white and 31 percent Black. With regards to age, 34 percent were 16–25, 31 percent were 26–35, 28 percent were 36–50, and 7 percent were older than 50.
The researchers used bivariate cross-tabulations and chi-square statistics to examine differences between the treatment group and their constructed comparison group. Ideally, these two groups would be the same except for the treatment group attending VIPs. However, the two groups differ significantly by age, race, and prior DUI convictions. The treatment group was younger, more likely to be white, and less likely to have had a prior DUI conviction. These differences were controlled for in subsequent analyses.
All research subjects were followed for 5 years using the National Crime Information Center (NCIC) records. This system allowed researchers to track subjects’ criminal record and their driving history to look for any DUI arrests. During those 5 years, reporting practices and laws for DUIs did not change, and the NCIC system tracked subjects even if they moved out of Clarke County. Police bias and discretion were further reduced due to the DUI task force established in Clarke County in 1992. When any police officer came across a drunk driver, the DUI task force was called in and took control of the case.