At the heart of our work is a strong belief in the merit of a diagnostic learning environment—one in which learners and learning are the focus and instruction respects and attends to developing individual learner’s thinking and understanding. The term “facet,” coined by Jim Minstrell in 1987 suggests this attention to the detail as it refers to the individual pieces of knowledge that all of us as learners use to construct understanding in a given situation.
A facet-based approach to learning recognizes that the complexity of teaching and learning cannot be rendered in a simple “right / wrong” scenario. Effective instruction at every age carefully considers the learner’s context, including prior knowledge and different ways of knowing and expressing knowledge. Consequently, we stress formative processes (from classroom assessment to program evaluation) in all areas of our work. We recognize cultural sensitivity and responsiveness as an integral part of approaching learning in all our work arenas in a “diagnostic” way.
Facets of student thinking
Facets of student thinking and the facet clusters are a framework for organizing the research on student conceptions in a way that is understandable to both discipline experts and teachers. Facets of student thinking assumes a "knowledge in pieces" perspective. However, those pieces are generally not as small as the phenomenological primitives (p-prims) used by diSessa (1993) and not as large as the "naive theories" suggested by McCloskey (1981.)
Facets are individual pieces or a few small pieces of knowledge and/or strategies of reasoning, which were derived from research on students' thinking and from classroom observations by teachers. They are only slight generalizations from what learners actually say or do, which makes them convenient units of thought for teachers and developers of assessment and curriculum materials as they make instructional decisions. Some facets are generic ("more is more") while others are content specific or strategic. The value of individual facets to the learner is frequently context dependent. Facet clusters are a sets of related facets grouped around explaining or interpreting a situation such as forces on interacting objects or around some conceptual idea like the meaning of average velocity. Facet clusters include the explicit learning goals in addition to associated reasoning, conceptual, and procedural difficulties. Each cluster builds up from the intuitive ideas students have toward the targets of learning. A full explanation and inventory of facets and facet clusters can be found at Diagnoser.com.