A Web-based instructional module for teaching middle school students engineering design with simple machines

Journal of Engineering Education, Oct 1998 by McKenna, Ann, Agogino, Alice

As the students work through their projects, they will be guided to use their developing knowledge to make predictions about possible solutions. They will then test their predictions through modeling and prototyping. Part of the design activities includes making sketches and calculations that describe and record the student's evolution of his or her design idea. This information will serve as a reference for the student if modifications need to be made. These records will also be part of a sharing activity that enables the student to make his or her thinking visible to the other class members. These activities model the engineering process described in figure 1.

The third cognitive goal is to enable students to make the connections between the physical devices and their governing abstract principles. A basic principle behind all of the simple machines is that of mechanical advantage. Simple machines were developed to allow people to perform functions that are difficult to accomplish with an individual's strength alone. When machines allow us to perform these functions they provide us with mechanical advantage. For example, some of the simple machines allow one to lift very heavy objects with little effort. The principle of mechanical advantage is translated for each of the machines and the students are expected to make the connections between the principles and the machines.

Students make these connections by engaging in the dual activities of physical manipulation and abstract simulation. The physical manipulations employ the Technic I set from LEGOTM,6 and the abstract simulations are embedded in the technology component. Therefore the student will see the principles represented in two different ways: 1) the simulations will provide an abstract representation and 2) the LEGOTM devices will provide a more concrete, physical representation. The students are then asked to compare these two results and draw conclusions about the functionality of each of the machines.

The fourth cognitive goal is to encourage students to selfreflect on their work and activities. While self-reflection is embedded in many of the activities already described, another specific self-reflection activity included in the module is the sharing of ideas. Students are expected to share their design ideas and any findings they made during the simulation and building process. The act of posting the results requires the students to reflect on what they have accomplished. Results are posted via the Internet to a bulletin board that is viewable by everyone, and students can comment on other students' work. Ultimately this questioning, and the resulting reflection required for responding, should lead to stronger student understanding.7,8

IV. USER INTERFACE DESIGN CONSIDERATIONS

In addition to the cognitive goals there were other considerations which guided the development of this module. While the user interface design is not part of the cognitive goals, it is still a critical component of the learning environment.