1999 Conference Attendee

Toward this end, Strawberry Creek employs a causal modeling tool which allows students to make and explain relationships between different factors (e.g. chemicals and organisms) in the creek. The particular nature of these relationships is represented through color, shape, and textual explanations. Students use the modeling tool to make initial predictions about the factors that contribute to water quality. As students explore online evidence about these factors, they iteratively refine their model. In addition to providing students with an external representation of water quality relationships, the tool also makes student thinking visible to the research team by logging changes to student models over time.

The study we report on explores changes in studentsí understanding of the role of phosphates and nitrates in the eutrophication of a body of water: where they are used, how they enter a water system, and their consequences on algae, bacteria, and other organisms in the stream. By helping to make student thinking visible, the modeling tool serves as an instructional scaffold for student learning. By tracking change to student models over time, the tool, combined with pre/post measures, serves an important assessment function that helps us to develop a deeper understanding of student learning about water quality as we iteratively redesign the curriculum.