Case Studies

Water Runoff Models Design Research

Goal of the Project: Design and iteratively refine and improve curriculum materials for elementary students that support them to develop a mathematical model of water runoff such that rainfall = water absorbed by the surface + water that runs off the surface. Students will then use that mathematical model to code a computational model that will allow them to test the amount of water runoff associated with different design solutions.

Phase 1 – Problem Definition
Goal: Identify challenges students were facing in learning about water runoff.
Methods: We qualitatively coded 895 student representations to identify patterns in students’ success and struggles with representing the science concepts.
Findings: Only 12% of students correctly showed the science concept that matter is conserved (rainfall = water absorbed by the surface + water runoff). Only 1 student did so consistently across all of the questions.

Phase 2 – Testing Solutions Case Study
Goal: Determine which supports are most effective for helping students attend to the conservation of matter in their models.
Methods: We developed two different supports, one was given to all three classrooms (75 students) the other support was presented differently to students by class section in a comparison test (50 students vs 25 students). We then used qualitative coding of student drawings (300 models) to identify patterns in the knowledge students represented in their models.
Findings: 80% of students correctly showed the science concept that matter is conserved. Students who were given more modeling support were less likely to show the processes that led to the science concept, and therefore showed less creativity in the ideas represented.

Impact: The proportion of students who successfully applied the mathematical model in their representations increased from 12% (in phase 1) to 80% (in phase 2).