Now that the engineer has some background information, some experimental result, and a good problem statement, (s)he will be ready to begin proposing design ideas. Using the information gathered and the criteria for success in the previous steps of the EDP, the engineer will think outside the box creatively when (s)he proposes solutions and develop a conceptual model of his/her design.
Designing models is a tool which allows the engineer to write procedures, determine materials needed, and decide on relevant data gathering techniques that will assist in evaluating his/her design. Although many models built are actual physical models of the proposed design solution, more and more engineers are using computer models and simulators to analyze their designs.
As the students take on the role of an engineer, they will analyze their solution, build models, and clarify concepts and explanations with teachers and other sources of scientific knowledge. In doing this, they engage in the explanation phase of inquiry. This step emphasizes the path from evidence to explanations based on evidence. Explanations go beyond current understanding and build on new ideas and understandings as the students discover, create, and "Propose Design Ideas."