Endless justification: A scoping review of team-based learning research in medical education.

As team-based learning (TBL's) popularity and implementation have expanded in medical education, so too have TBL studies and accompanying research syntheses. However, earlier reviews hint that the scope of TBL research is narrow and our own observation is that it seems to lack progression. To examine this, our research question was: What is the state of TBL scholarship in medical education, and how has empirical research on TBL in medical education changed over time? We conducted a scoping review of published research. On 4 April 2024, we performed a search across multiple databases (Medline, Embase, PubMed, CINAHL, Web of Science, ERIC, and Scopus). We included empirical studies published in English that reported on TBL in medical education. The studies were analysed for study characteristics, research foci and research type (description, justification and clarification). We identified and analysed 288 empirical studies. These primarily used quantitative descriptive methods, most commonly surveys. Research often focussed on comparing TBL to other learning approaches. Most studies examined individual characteristics, learning outcomes and/or student engagement. Descriptive studies were commonplace (33%), but the field was largely dominated by justification studies (52%). In contrast, clarification studies, those examining 'how' and 'why' TBL works, were relatively rare (15%) overall, and remained proportionally fewer over time than descriptive and justification studies. While we can safely say that TBL is just as effective as other educational approaches in terms of learning outcomes, key claims about TBL remain largely unexplored. Instead, TBL research seems to be stuck in justification rather than following a scientific line of pedagogical inquiry where one study is the foundation for the next. Critical examination of TBL is long overdue to bring greater understanding of the nature and effects of this pedagogical intervention on teaching and learning processes in different contexts.