RESUMO
Yoga is a multidimensional and heterogeneous mind-body practice led by a therapist or teacher (e.g., yoga instructor). Although they constitute an integral part of delivery, content, and curriculum, factors that influence yoga instructors' choices have yet to be explored. Using a mixed methods sequential design for development of an instrument that identifies measurable epistemic (YIBS-E) and pedagogic (YIBS-P) beliefs, the Yoga Instructor Beliefs Scale (YIBS) reports validity evidence from four distinct phases. Phase I presents qualitative findings from literature-informed semistructured interviews to give a comprehensive construct model of yoga instructor beliefs from diverse styles/ schools/lineages of yoga (nine content-specific clusters). In Phase II, focus group panels of experts evaluated construct novelty and importance of themes, resulting in a pool of potential questionnaire items. Phase III employed cognitive interviews to assess the perceived meaning and clarity of using the preliminary YIBS items. Phase IV included exploratory factor analysis and correlational analyses using 204 yoga instructor responses, suggesting a 44-item instrument with distinct epistemic (Experiential, Energetic, Systems-Based, Affectual, Mindful, and Physical) and pedagogic (Curricular Integration, Student Awareness, Accessibility, and Differentiated Instruction) factors (YIBS- E α = 0.90, YIBS-P α = 0.85). Measurable belief constructs can inform research on individual yoga instructor differences that may influence curriculum content choices and delivery. The purpose of this instrument is to enable research linking instructor beliefs to the presence of various components of a yoga program and to contextualize defining qualities of yoga programs. Long-term use of this instrument should enable in-depth analyses such as mediation or moderation of yoga instructor beliefs on intervention components/content or outcomes.