Purpose
Our educational program uses TBL to assess and extend small group Case-Based-Learning (CBL), which is considered the pre-work for TBL. In this intervention, funded in part by TBLC, students were assigned to work with the same “static” group for TBL as for CBL or a “hybrid” group comprised of members from 6-7 different CBL groups. The study aims were (1) compare outcomes and experiences of students on hybrid versus static teams; (2) understand student perspectives on these curricular choices.

Methods
Data were collected over three years. In Years 1 and 3, the intervention ran during two courses. Each group was “static” for one and “hybrid” for the other. IRAT, GRAT, GAE, and exam scores for questions mapped to TBL were compared between conditions using a two-tailed t-test. Pandemic circumstances prohibited intervention in Year 2; those data are analyzed as control. Students completed surveys (n = 96) and focus groups (n = 7) on their experiences. Responses were analyzed thematically.

Results
There were no significant differences in exam scores between static and hybrid groups.
Across all years, in course 1, hybrid groups performed significantly better on IRAT; in course 2, static groups performed significantly better in GAE; the same groups performed significantly better in GRAT regardless of hybrid or static condition. In course 2, hybrid groups scored significantly higher in GRAT in Year 1, and static groups scored significantly higher in GAE in Year 3. Survey respondents rated static better for learning the material, speed of learning, depth of knowledge, additional stress, and preference. Qualitative results demonstrated mixed sentiments.

Conclusions
Multiple peer-based learning groups do not consistently impact academic outcomes. Educators could pursue either condition based on their mission and goals. Educators using hybrid groups should address student concerns regarding increased stressed and negative impacts on perception of learning.