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A "How it Works" sheet is one on which students describe a mechanism and show how it works. It should be mostly graphical, with as little text as is needed for clarity. Two page spreads work well, but one page may be sufficient for simpler objects. This can be used with items the students design themselves, or ones they observe in other places. Either way, it teaches them to look carefully at how things work and express their ideas through sketches and text.
Often in engineering, the people in charge of design are not the same as those in charge of manufacturing. "Over the wall" exercises help students create and read technical drawings, either formal or informal. Students (either individually or in teams) are assigned a design project and told to brainstorm ideas and then sketch -- but not build -- their favorite solution. The sketches are then collected and handed out again to different students, who are responsible for implementing the ideas. If done with a project that is suitable for prizes, both the designers and manufacturers of the winning project should be rewarded.
Many student projects are so time pressured that students do not prototype to find the best solution, and settle on a solution too early in the design process. Assigning the same project twice allows the students to go through the redesign process, something real engineers do many times before a product goes to market. Having a chance to see where their own designs succeeded and failed, and the strengths and weaknesses of other students' designs, allows students to create a better design the second time, and teaches them to be critical of their designs and think up better methods-- even after the due date. Students can each redesign again from the ground up, or one project may be chosen as the starting point and all students or groups can modify that design. Improvements will be apparent in any type of project, but in projects with specific, measurable goals, such as tower height or bridge strength, they can be numerically compared to show students their improvement. Very short projects can even be done and then redesigned within the same class period with good results.
A reflection assignment can allow the students many of the benefits of redesign without the time commitment. During the original project demonstration, have students walk around and look at other designs, making notes and sketches on designs they particularly like. Then have them write a short paper (one page is plenty, half text and half illustrations) comparing their design to the one they liked best, and explaining how they would change or improve their design if they had to do it again.
Most design projects can be done individually or in groups. Both methods have their advantages. Individual work ensures that each student participates and gains an understanding of the principles involved, as well as eliminating scheduling conflicts, which can be critical in large groups, especially for short term projects. However, engineers must be able to work in teams. Group work teaches students how to work together and teach each other, and usually results in more creative solutions. If groups are used, it is important to make sure group members have a variety of skills, and that everyone participates. It can not be assumed that students, even at the university level, know how to work in groups, and it may be necessary for the instructor to facilitate teamwork. It may be helpful to have students do reflection papers on their groups as well as on their projects, analyzing how well their groups worked together and what they could have done better. A simple method for dividing the class randomly into teams of four is to pass out a playing card to each student, and have students with the same number work together.
Many of the shorter projects can be done either in class or at home. In class projects teach students to work quickly and think on their feet. They can also be done more easily as "over the wall" exercises. The same project done at home will be more thoughtful, and thus probably more creative, better constructed, and allow for more iterations of the design process. One way to reinforce both types of thinking, as well as expose the students to redesign and reflection, is to go through a project in class and then assign it as a take home project due the next class period. The second round projects should be much better because the students have had exposure to a variety of designs, both good and bad, in class, and then the time to process that exposure.
Grading open-ended design projects can be very difficult. Clever designs,
even when well constructed, will sometimes fail, while simplistic or poorly
constructed designs will sometimes succeed. It is important to reward students
for all types of success, especially since they will have had different
levels of prior exposure to design and construction. It may be helpful
to have a "standard" or "expected" grade which the majority of students
receive on the majority of their work. This standard grade will be given to
assignments that are thoughtful and well presented, whether or not they succeed
in the task given, and will encompass a wide range of results. Only
exceptional work will receive a higher grade, and only work which is obviously
thrown together at the last minute or sloppily presented will receive a lower
grade. In class work should be graded on participation alone, since it does
not give students the opportunity to provide their best work.
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