BACKGROUND: Clinical supervisors make frequent assessments of medical trainees' competence so they can provide appropriate opportunities for trainees to experience clinical independence. This study explored context-specific assessments of trainees' competence for independent clinical work.

METHOD: In Phase One, 88 teaching team members from internal and emergency medicine were observed during clinical activities (216 hours), and 65 participants completed brief interviews. In Phase Two, 36 in-depth interviews were conducted using video vignettes. Data collection and analysis employed grounded theory methodology.

RESULTS: Supervisors' assessments of trainee trustworthiness for independent clinical work involved consideration of four dimensions: knowledge/skill, discernment of limitations, truthfulness, and conscientiousness. Supervisors' reliance on language cues as a source of trustworthiness data was revealed.

CONCLUSIONS: This study provides an initial exploration of context-specific competence assessments, which affect both patient safety and education, and provides a novel framework for study of the links between language use and competence.