Workshops: Product Dissection (An Engineers Eye)
Technology touches today's teens, from their compact disc players to their hair dryers and pocket calculators. Rarely, though, do they consider how machines and technology - and the engineering that makes them possible - affect their lives.
The overall objectives of this exercise are to allow the students to see first-hand the:
This exercise, done in teams of two or three students, is designed to give students an opportunity to take a machine or device apart; this is referred to as "dissection". We often take for granted how machines affect our lives, and seldom consider the inner workings of these devices. We also fail to acknowledge the engineers who designed and built them.
On a per team basis (teams are comprised of two or three students):
While the exercise can be run effectively with a single instructor, it makes the entire experience much more personal if there are a number of assistants (sometimes referred to as coaches) who can aid the student teams through the disassembly stage. Assistants can be the regular classroom teacher, undergraduate/graduate engineering college students, and/or other practicing engineers. You and your assistants will want to become thoroughly familiar with the device to be dissected as well as general administration of the exercise in advance of the class session. Using assistants will help give the students a broader picture of "what engineers look like", so if possible strive for diversity in your assistant pool; you might also selecting assistants who represent different engineering disciplines. For a class of 30 students, two assistant plus the instructing engineer work well.
Recommended prerequisites for device selection are that it:
Items that typically cost less than $5 each:
Other suggested devices/machines:
Where to find devices (and other ideas):
Prior to your session with the students, you need to become the "expert" with the device. Take it apart and put it back together enough times so that you have a good feel for the difficulties involved. If there is some aspect of the disassembly or reassembly that is particularly tricky, consider creating a simple handout on the procedure. In addition, go over the exercise with your assistants and with the regular classroom teacher. Discussing the exercise with the teacher will help you:
Now for you class visit.
Remind students that they are responsible for disassembling and reassembling the device as well as answering the questions (in words or sketches).
As the student teams are disassembling you and your assistants should wander among the groups, lending suggestions when they seem to be having a difficult time understanding a particular aspect of the device, or asking them probing questions about what they are seeing. Do not assume that all of the students have been taking things apart since they were little and know even which way to turn the screwdriver to remove a threaded fastener.
Have everyone stop working and have one member of each team orally present the team's answers; record the answers on the blackboard or butcher paper. Butcher paper is nice in that it leaves the classroom with an artifact of the experience.
You might have the first group report on Question #1, then have the second group answer Question #2 - adding any details to the answer for Question #1, etc. When talking about the types of engineers involved in creating the device, be sure the list reflects the breadth of the engineering profession (e.g., materials engineers, industrial engineers, environmental engineers, etc.)
You could leave the devices in the classroom for further exploration and/or complete reassembly. Also suggest other devices/machines that students might like to take apart, and where they might find inexpensive samples (e.g., secondhand stores, garage sales). They could even "play doctor" with machines that no longer function in terms of diagnosing what is wrong.
All ages like the idea of "sanctioned" disassembly. With the middle school students you may want to focus more on the science integral to the device than the specific roles that engineers played in its creation (if only because career decisions are a bit more remote for this age); you might also talk with the classroom teacher beforehand concerning the level of career readiness of the students.
1. The Way Things Work by David Macaulay, Houghton Mifflin Company, 1988.
2. How Things Work by the Editors of Consumers Guide, Publishers, International, 1990.
This activity provided by The Synthesis Engineering Education Coalition. Funded by the National Science Foundation, the coalition is charged with the task of reshaping undergraduate engineering education while increasing the participation of those currently underrepresented in technical disciplines. Member universities include Cal Poly-San Luis Obispo, Cornell, Hampton, Iowa Sate, Southern, Stanford, Tuskegee, and the University of California at Berkeley. (For more information contact Dr. Sheri Sheppard in the Design Division of the Mechanical Engineering Department at Stanford University, 415-725-1590 or Sheppard@sunrise.stanford.edu)