Implicit Assumptions and Progress Variables in a Learning Progression About Structure and Motion of Matter

Abstract

This chapter presents one iteration in the refinement, or validation, of a learning progression of the structure of matter. The initial, hypothetical particulate nature of matter learning progression described likely pathways in the development of learners’ implicit assumptions, which are presuppositions about the nature of entities that guide and constrain people’s reasoning involving those entities. Refinement of the learning progression involved developing an assessment to measure which implicit assumptions are held about the structure and motion of matter by students aged 13 to graduation from university. The development of this previously published assessment based on the phenomenon of diffusion is briefly summarized in the service of showing that the instrument’s use with a large sample of students permits the clarification of progress variables. Progress variables allow for measuring the occurrence of more sophisticated implicit assumptions to be determined by ascertaining students’ thinking patterns. Examples of students’ responses to survey questions are provided to illustrate how the implicit assumptions constraining students’ thinking are evident in different thinking patterns along two of the progress variables. The iteration – from hypothetical learning progression to development of an assessment to measure students’ implicit assumptions to interpretation of student data – served as a validation cycle that refined the learning progression. It also lent insight into how the curriculum in use in the schools from which the participants were drawn shaped the students’ development of particular implicit assumptions.