Supporting Preservice Teachers’ Use of Modeling: Building a Water Purifier

Abstract

Research has shown the value of modeling as an instructional practice. As such, instruction that includes modeling can be an authentic and effective means to illustrate scientific and engineering practices as well as a motivating force in science learning. Preservice science teachers need to learn how to incorporate modeling strategies in lessons on specific scientific topics to implement modeling practice effectively. In this article, we share an activity designed to model how the effectiveness and efficiency of a water purifier is impacted by creating a primary purification medium using different grain sizes and different amounts of activated charcoal. We seek for the preservice science teachers to learn how modeling is a process that requires revision in response to evidence. The water purifier activities in this paper were adapted for use in a secondary science teacher preparation program during the fall semesters of 2015 and 2016 as a means to introduce an effective modeling activity that is in the spirit of NGSS. These activities also support preservice teachers’ development of teacher knowledge relative to ‘model-based inquiry’ as well as teaching systems thinking. In addition, preservice science teachers learn how to think of modeling as an assessment tool through which they might gauge students’ understanding. Modeling may be used as a form of authentic assessment where student accomplishment is measured while in the act of constructing a model, revising a model or any of the other modeling related processes.