Thinking About Simple Machines: Model-Based Reasoning in Design Contexts

In this project a series of teaching studies is used to investigate how elementary school teachers can use design contexts to support the learning of mathematics and science. During the past six months researchers have been working on developing design contexts that can be used across elementary school grades, with the understanding that younger children and older children will enter the task at different points and progress at different rates and in different ways. The value of cross-grade design tasks is that they focus teachers' attention on the development of student reasoning beyond the boundaries of one grade level.

During the 1996-97 school year the project worked in consultation with physicist Ted Ducas from Wellesley University to develop and include design contexts in feature architecture--specifically, the design of tents, architectural structures in which the primary explanatory principles involve tension rather than compression, which is more commonly invoked in architecture. Design projects with tents involve students in reasoning about geometry (surface area and volume), properties of materials, and environmental considerations.

As curricular foundation for earlier years' work on biomechanics, researchers are developing a set of related classroom projects that explore the properties of levers of all three classes. To support this work with primary grade students, the project is developing a device that affords exploration of forces applied in various directions on a lever arm with a movable fulcrum. The intention is to develop curricular approaches that will connect foundational ideas about levers to a wide variety of phenomena, from the operation of parts of the human body to curve-drawing devices.