JOURNAL OF RESEARCH IN SCIENCE TEACHING VOL. 47, NO. 6, PP. 687–715 (2010) Developing a Hypothetical Multi-Dimensional Learning Progression for the Nature of Matter Shawn Y. Stevens, Ce ´sar Delgado, Joseph S. Krajcik School of Education, University of Michigan, 610 East University Avenue, Ann Arbor, Michigan 48109-1259 Received 10 July 2008; Accepted 12 June 2009 Abstract: We describe efforts toward the development of a hypothetical learning progression (HLP) for the growth of grade 7–14 students’ models of the structure, behavior and properties of matter, as it relates to nanoscale science and engineering (NSE). This multi-dimensional HLP, based on empirical research and standards documents, describes how students need to incorporate and connect ideas within and across their models of atomic structure, the electrical forces that govern interactions at the nano-, molecular, and atomic scales, and information in the Periodic Table to explain a broad range of phenomena. We developed a progression from empirical data that characterizes how students currently develop their knowledge as part of the development and refinement of the HLP. We find that most students are currently at low levels in the progression, and do not perceive the connections across strands in the progression that are important for conceptual understanding. We suggest potential instructional strategies that may help students build organized and integrated knowledge structures to consolidate their understanding, ready them for new ideas in science, and help them construct understanding of emerging disciplines such as NSE, as well as traditional science disciplines. ß 2009 Wiley Periodicals, Inc. J Res Sci Teach 47: 687–715, 2010 Keywords: learning progression; secondary; qualitative; integrated knowledge; undergraduate Recent scientific research has revealed that matter exhibits novel, often unexpected properties as it transitions between the bulk form and that of individual atoms and molecules. This transition generally occurs at the nanoscale, where at least one dimension measures between 10 9 and 10 7 m. Scientists and policy-makers predict that the new information and technologies resulting from nanoscale science and engineering (NSE) research will have extensive societal implications that may be realized in a broad range of areas, including health care, agriculture, food, water purification, and energy and environmental concerns (PCAST, 2005). These predictions have created a need to incorporate ideas related to NSE into the science curriculum. A foundation for NSE literacy must include a robust model of the nature of matter, which includes the structure of matter, how it behaves and interacts, as well as its properties and what determines those properties. These ideas are also the foundation of understanding chemistry and are considered important aspects of science literacy (American Association for the Advancement of Science [AAAS], 1993; National Research Council [NRC], 1996). Due to the extensive nature of the science content, we will focus on only a portion of it in this manuscript. We describe our efforts toward the development of a hypothetical learning progression (HLP) that characterizes a path along which grade 7–14 students may develop more sophisticated models of atomic structure, and the electrical forces that govern interactions at the nano-, molecular, and atomic scales. Each of these knowledge domains represents a significant portion of one or more big ideas of NSE (Stevens, Sutherland, & Krajcik, in press). We followed an iterative, design-based research process to ensure the science content, the instructional strategies to help students to develop understanding of the content, and assessments to place students along the HLP were aligned. Contract grant sponsor: National Science Foundation; Contract grant numbers: 0426328 and 0822038. Correspondence to: S.Y. Stevens; E-mail: sstevens@umich.edu DOI 10.1002/tea.20324 Published online 5 August 2009 in Wiley InterScience (www.interscience.wiley.com). ß 2009 Wiley Periodicals, Inc.