Modeling is a core practice in science and a central part of scientific literacy. We present theoretical and empirical motivation for a learning progression for scientific modeling that aims to make the practice accessible and meaningful for learners. We define scientific modeling as including the elements of the practice (constructing, using, evaluating, and revising scientific models) and the metaknowledge that guides and motivates the practice (e.g., understanding the nature and purpose of models). Our learning progression for scientific modeling includes two dimensions that combine metaknowledge and elements of practice-scientific models as tools for predicting and explaining, and models change as understanding improves. We describe levels of progress along these two dimensions of our progression and illustrate them with classroom examples from 5th and 6th graders engaged in modeling. Our illustrations indicate that both groups of learners productively engaged in constructing and revising increasingly accurate models that included powerful explanatory mechanisms, and applied these models to make predictions for closely related phenomena. Furthermore, we show how students engaged in modeling practices move along levels of this progression. In particular, students moved from illustrative to explanatory models, and developed increasingly sophisticated views of the explanatory nature of models, shifting from models as correct or incorrect to models as encompassing explanations for multiple aspects of a target phenomenon. They also developed more nuanced reasons to revise models. Finally, we present challenges for learners in modeling practices-such as understanding how constructing a model can aid their own sensemaking, and seeing model building as a way to generate new knowledge rather than represent what they have already learned. ß 2009 Wiley Periodicals, Inc. J Res Sci Teach 46: 632-654, 2009 Keywords: scientific modeling; learning progression; scientific practice; student learningResearch-based reforms in science education have emphasized the importance of engaging learners in scientific practices-social interactions, tools, and language that represent the disciplinary norms for how scientific knowledge is constructed, evaluated, and communicated (Duschl, Schweingruber, & Shouse, 2007). Involving learners in developing and investigating explanations and models leads to more sophisticated understanding of key models in science, as well as helping learners understand the nature of disciplinary knowledge (e.g., Lehrer & Schauble, 2006). Yet, scientific practices require shifts in traditional classroom norms that involve learners in knowledge building and negotiation (Berland & Reiser, 2009; Jimenenez-Aleixandre, Rodriguez, & Duschl, 2000;Lemke, 1990). For effective participation in scientific practices, teachers and students need support with the practices as well as with the scientific ideas addressed by the practice (Duschl et al., 2007).The MoDeLS project, Modeling Designs for Learning Scien...

Recent research and policy documents call for engaging students and teachers in scientific practices such that the goal of science education shifts from students knowing scientific and epistemic ideas, to students developing and using these understandings as tools to make sense of the world. This perspective pushes students to move beyond the rote performance of scientific actions or processes and engage instead in purposeful knowledge construction work. This raises parallel questions about how to go beyond characterizing student performance of scientific process to understand their engagement in scientific practices as a goal-directed activity. To that end, this article offers a framework-the Epistemologies in Practice (EIP) framework-for characterizing how students can engage meaningfully in scientific practices. This framework emphasizes two aspects of student engagement in scientific practices: (1) the students' epistemic goals for their knowledge construction work and (2) their epistemic understandings of how to engage in that work.

This article describes revisions to four of the eight constructs of the Duncan molecular genetics learning progression [Duncan, Rogat, & Yarden, (2009)]. As learning progressions remain hypothetical models until validated by multiple rounds of empirical studies, these revisions are an important step toward validating the progression. Our revisions are based on empirical data obtained from tenth grade students in three classroom contexts (n ¼ 121); although our study was done with students at the upper bounds of the progression, students held naive ideas prior to instruction which allowed us to track their ideas through all the levels of each construct during the course of one academic year. We revised the four constructs that center around the molecular model of genetics using students' pre/post assessments and interviews. We found that tenth grade students do hold ideas consistent with the hypothesized levels in the progression as well as several intermediate ideas not included. Our revisions include adding student ideas that are important conceptual stepping stones in each construct as well as other modifications such as splitting and combining levels, moving ideas to other constructs, changing the conceptual progression of a construct and splitting a construct. Along with the revisions, we identified challenges in each construct. Even after instruction, students had difficulties understanding that genes code for proteins, that proteins connect genes and traits, and how differential gene expression leads to different repertoires of proteins inside of specialized cells. Our findings indicate that classroom instruction should focus more on proteins: how they are created, what their functions are, and how cells express different proteins.

No abstract

No abstract