In spite of steady growth and wide support, shock incarceration programs remain poorly understood, according to National Institute of Justice researchers. Basic tenets of shock incarceration programs are participation in a sentencing alternative to a longer prison term, a military "boot camp" regimen, and the separation of shock-incarceration participants from other prison inmates. Beyond these broad components, however, the profiles of individual programs can be significantly different. MacKenzie's evaluation of the Louisiana program in 1993 and the same team's subsequent evaluations of programs in eight States examined the programs' effect on deterrence, recidivism, prison crowding, and offender attitudes. Although the programs' impact on offender attitudes was generally positive, the findings on other measures were less encouraging. A more recent study of Justice Department researchers specifically examined boot camp drug treatment and aftercare intervention. Researchers found that although reducing offender drug use was indicated as a priority for most programs, there was considerable confusion about what constitutes drug treatment. It is likely that the future of shock incarceration will involve refinements and restructuring of programs based on the recent findings of researchers as well as site-based experience. The trend for some programs is to de-emphasize the military regimen and focus more on treatment regimens, such as vocational training and community service. Continued research that aims at improved and standardized evaluations may help bring policymakers closer to an answer about the value and effectiveness of the various types of shock incarceration programs. 23 notes