Using learning progressions to describe how students develop increasingly sophisticated understandings of biodiversity

Background/Question/Methods

We will illustrate a learning progression approach to understanding how grades 6-14 students develop a more sophisticated understanding of an important ecological concept, community assembly.  Specifically we will describe how we have integratively developed and used learning progression frameworks, assessments, and instructional resources.  First, we proposed a set of progress variables.  Progress variablesare topics that are important for understanding biodiversity (e.g. organismal interactions) that all students, regardless of grade-level, can engage in.  For each progress variable, we described the knowledge and practices that experts believe graduating high school students can and should have; this is the upper anchor of the progression.  We then developed and used written and interview assessments of students to empirically determine the lower anchor, what 6^th grade students know, and the intermediate level descriptions in our progression.  Using this framework we created instructional resources for middle school, high school, and beginning college classes.  These resources were explicitly designed to give students experiences to move them toward the upper anchor.

Results/Conclusions

Trends in student understanding: We found that young students reason about the natural world using inappropriate anthropomorphic analogies.  For example, they describe interactions between organisms based on human-like emotions (e.g., like, dislike, helping, harming) and attribute behaviors of organisms as guided by free will or enlightened self-interest.  As students progress, they replace inappropriate analogical reasoning with appropriate analogical reasoning (e.g, all organisms must reproduce) and reasoning based on scientific principles and models.  In particular, students move from reasoning only about actions of individuals to reasoning about populations within communities and ecosystems.  They expand their temporal reasoning and move from thinking that environments and communities are static to recognizing relevance of change over time in individuals, populations, and communities.  They refine their spatial resolution abilities (i.e. microhabitat) and expand spatial scales of reasoning (i.e. communities are nested within a surrounding matrix).  

Nature of Successful Assessment and Instructional Approaches: Ecosystems are complex systems governed by many principles that vary in their importance depending on ecosystem context.  Because of this, we have made our best progress using a “scenario” structure that 1) provides a rich context for students to apply principles through a series of related assessments or activities and 2) specifies a set of temporal relationships that make it possible to assess whatever combination of principles and characteristics we want to focus on.