A Review of Optimal Group Size and Modularisation or Continuous Entry Format for Program Delivery

Why we did this study

Correctional Service of Canada has a responsibility to provide federally sentenced offenders with effective correctional programming to promote successful reintegrating into the community. The challenge is to identify appropriate strategies to facilitate the efficient delivery of these programs, without compromising program quality and public safety. Certain factors, such as larger group size and modular program delivery format could increase the numbers of offenders who could participate in programs but could also have an effect on offenders' response to the program material. The Transformation Team asked the Research Branch to review the literature and input of stakeholders regarding the optimal group size as well as the feasibility delivering programs in a continuous entry or modularised format.

What we did

To examine the issue of optimal group size, we reviewed the literature on group therapy and programs. Research on programs from correctional settings as well as non correctional community settings was also examined. To examine the issue of continuous entry and modular entry format, interviews were conducted with CSC facilitators who have used both the modular or continuous entry format and the closed group format. Interviews were conducted with facilitators from all regions; facilitators had at least two years of experience delivering programs.

What we found

The literature does not provide strong empirical evidence for an optimal group size; however, practitioners consistently recommended that optimal group size with one facilitator is 6-8 members. The literature also stressed that optimal group size is dependent on the goals of the program, the profile of the participants, and the requirements of the agency. Given the unique needs of offenders in CSC programs, group size should probably not exceed ten participants.

Program facilitators responded that a key strength of the modularised program delivery format is its ability to reduce delays in starting a program. The review suggested that modularised program delivery works best when the group is homogenous with respect to presenting problem; participants are not high risk and high need, participants are already familiar with similar program content; and the program is delivered in the community. While modular delivery may be too administratively difficult to implement for high need and high risk offenders who take programs at institutional sites, some sites outside of CSC have been successful in offering a continuous entry (rolling) programs to offenders.

What it means

No practitioner in the literature reviewed recommended a group size of over ten unless it was a psychoeducational group. Correctional programs in CSC are already at the limit of the recommended group size given the challenges of the population. Results also suggest that modular program delivery is probably not recommended for institutional programming with high risk and high need offenders; however, a continuous entry format with offenders who have previous program experience has worked well in community settings within CSC.

For more information

Stewart, L., Usher, A., & Allenby, K. (2009). A review of optimal group size and modularisation or continuous entry format for program delivery Research Report R-215. Ottawa: Correctional Service Canada

To obtain a PDF version of the full report, contact the following address: research@csc-scc.gc.ca

Prepared by: Stewart, Lynn


Research Branch
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