Using Primitive Engineering as a Tool for Introducing Engineering Design Concepts for K-12 Outreach: Experiences with Trebuchets and Waterwheels

We have tried many approaches for introducing engineering concepts to K-12 students under the Southern Arizona MESA (Math Engineering and Science Achievement) program, but none has been more successful than the emulation of primitive engineering as a vehicle for conveying basic concepts in an accessible yet challenging manner.The harnessing of mechanical forms of energy, by using the force of falling water, or by mastering the use of fulcrums, levers, and weights were among the earliest achievements that in modern times we might recognize as "engineering."By extension, our hypothesis is that the engineering concepts central to the design of primitive machines may be as accessible and understandable to untrained K-12 students as they were to the primitive peoples who first harnessed them.We have analyzed and experimented with two types of primitive machines as tools for engineering outreach, the first being the Waterwheel, and the second being the Trebuchet.The latter is a specialized name for a counter-weight catapult, a device for throwing a projectile by using the energy of a falling counterweight to power it.We have developed learning modules for K-12 students based on the discussion and analysis of each of these machines with the two central tenets: (1.) However primitive, these are engineering machines and we can learn about engineering by understanding them, (2.)The design of the machines was originally evolutionary, but today we would follow a systematic process which we systematize as Engineering Design.This paper discusses the structure and content of the Waterwheel and the Trebuchet learning modules.Structurally, the modules have four components: Introduction of concepts; Machine Conceptualization, Modeling and Simulation, and Empirical Validation.This paper will primarily focus on the development and use of simple modeling and simulation concepts, their validation by simple experiments, and discussion of early experiences with the use of the modules in outreach to K-12 underrepresented student populations.Our most important finding to date is that the use of visual "design" tools based on easily graspable physics, in addition to the "building and trying" of simple machines such as these, is an effective way to introduce the notion of engineering models and simulation and why they are important in the design of modern machines.