Supporting Valid Interpretations of Learning Progression Level Diagnoses

Assessments associated with learning progressions are designed to provide diagnostic information about the level and nature of student understanding. Valid interpretations of such diagnoses are only possible when Students consistently express the ideas associated with a single learning progression level. Latent class analysis was employed to evaluate whether patterns of expected responses to diagnostic multiple-choice items afforded valid interpretations of learning progression level diagnoses. Results indicated that students with scientifically accurate understanding of the forces acting on ail object with constant speed usually reasoned systematically across items, but many other students did not. Consequently, interpretations of learning progression level diagnoses on a proposed learning progression would often be invalid. Analyses of this sort would be useful in developing and validating future learning progressions. (C) 2009 Wiley Periodicals, Inc. J Res Sci Teach 46: 699-715, 2009