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4.6: Instructor Supplemental Resources

Created by: CK-12

Standards

ASEE Draft Engineering Standards. This chapter is focused on “Dimension 1: Engineering Design” of the ASEE Corporate Members Council Draft Engineering Standards; these draft standards will serve as input to the National Academy of Engineering process of considering engineering standards for K-12 education. This dimension includes the following outcomes:

  • Students will develop an understanding of engineering design.
  • Students will apply the engineering design process, troubleshooting, research and development, invention and innovation, and experimentation in problem solving and engineering design.

Common Preconceptions

The following are preconceptions and tendencies that novice designers may exhibit:

  • The novice designer tends to believe that design is primarily developing creative or novel ideas (e.g., brainstorming), and does not understand the role or importance of iteration, evaluation, and planning.
  • Novice designers show an inability to evaluate and recognize quality ideas and to discriminate between effective and ineffective design processes.
  • Novice designers often have difficulty clearly defining the problem in the context of the user’s environment and constraints.
  • Novice designers often focus on a single idea without considering alternatives (often the first idea that comes to mind).
  • Novice designers are often unaware of the difference between an abstract concept and a detailed design, and do not use appropriate tools and processes to go from the abstract concept to the detailed design.
  • Novice designers often see design as a strictly serial process and do not recognize the need for iteration, revisiting past decisions, and evaluating alternatives.
  • Novice design teams often exhibit poor team decision making.

The idea that a design is a decorative pattern may be a preconception. Students may not understand that another meaning of design is a representation of the appearance and function of an object before it is made.

Students may also have preconceptions about models. The most important are that models are always physical and that models have a one to one correspondence with reality. Students do not understand that models often leave out important aspects found in the real object or system.

Bibliography and References

  • Clive L. Dym and Patrick Little. Engineering Design: A Project-Based Introduction. Wiley, 1999.
  • Michael McCracken, Wendy Newstetter, and Jeff Chastine. “Misconceptions of Designing: A Descriptive Study.” Proceedings of the 4th annual SIGCSE/SIGCUE ITiCSE Conference on Innovation and Technology in Computer Science Education, Cracow, Poland, 1999.

Project—Design a Solar Cooker

Goal: students will engage in the engineering design process. To the extent possible, the emphasis in the activity should be on the process, and not on the designed artifact; students tend to focus on the object being designed and not see that the quality of the process determines the quality of the design. Novice designers should demonstrate awareness of their design process and see where they have or have not used elements of the design process. Experienced designers should follow a design process and be able to identify the strengths and weaknesses of their process.

This project activity is structured using the 5E Learning Cycle.

Objectives

Students will recognize that design is a process and understand that the quality of the process affects the quality of the resulting design. Students will be able to apply each step of the engineering design process to design a solar cooker.

Materials

The activity requires materials to build a simple solar cooker. Since the emphasis of the activity is on the design project, it would be helpful if there is a wide range of available materials. Possible materials could include

  • Cardboard boxes (shoe box or larger size).
  • Cardboard.
  • White and black paint.
  • Transparent materials such as plastic wrap, clear hard plastic, and glass.
  • Reflective materials such as aluminum foil or unbreakable mirrors.
  • Packing tape or duct tape.
  • Stiff wires or skewers.

The following tools will be needed:

  • Scissors
  • A thermometer capable of measuring up to 250 degrees Fahrenheit.

Engage

The teacher engages the students in a discussion of how much of their environment has been designed by humans. For example, if the class is in a building, it is a building that people designed, engineered, and constructed. The teacher points out that almost every aspect of modern life depends on and is affected by technological artifacts such as bridges, buildings, vehicles, cell phones, computers, and so on. These technological artifacts are designed and created by engineers using the engineering design process.

Students complete the first two columns of the KWL chart (What I know, What I Want to Know) in Table 2, indicating what they know about the design process and what they want to learn.

KWL Chart for engage activity.
What I Know What I Want to Know What I Learned

The teacher then explains that the engineering design process is used to solve problems, and shows examples of deforestation caused by people collecting wood to be used in cooking fires. For example, Figure 18 shows a man carrying firewood in Mozambique. (Haiti is another source that provides a dramatic example of the problem.) The teacher engages the students in a discussion about alternative methods of cooking food in developing nations. Solar energy is one potential alternate energy source; Figures 19 and 20 show two devices that use solar energy to cook food.

A man carrying firewood in Mozambique. Firewood is the primary source of energy for cooking food; collection of firewood in many developing countries has led to severe deforestation.

A simple solar oven made out of a cardboard box, foil, and clear plastic.

A solar cooker and a solar water heater in India. The solar water heater is on the roof of the building. The solar cooker is the silver dish in front of the building.

Explore

Students are given the problem of designing a method of cooking food using solar energy as a feasible alternative to collecting fire wood. Working in teams, they use the Internet and other sources to collect information to understand the design characteristics necessary for a solar cooker to be useful in a developing country. They organize and report this material to the class.

Then students work in teams to develop a design concept and document the concept with a detailed drawing. The idea here is that students will employ an ad hoc process that becomes the basis for discussion as they go through the Explain process.

Explain

The design process is explained to the students using the material in this chapter; the students are exposed to the steps of the design process. They compare and contrast the process they used in the explore activity with the design process covered by the teacher. They also complete the right column of their KWL chart.

Extend

Student teams go through a scaffolded design process to create and evaluate a prototype of a solar cooker. This process need not include all of the steps described in the Introduction to Engineering Design chapter, particularly for novice designers. As students work through each step in the design process, some scaffolding should be provided; for example, each team may report its work on each step to the class and receive formative feedback on their work before moving on to the next step. In addition, the way in which each step is performed may be tailored to the developmental levels of the students. Novice designers may be asked to concentrate on the outcome that should be produced, while more advanced designers may be asked to employ some or all of the tools identified it the Introduction to Engineering Design chapter.

The following gives information on some of the design process steps that could be required of the students.

Identify Criteria and Constraints

Students develop criteria and constraints for the problem of designing a solar cooker. Examples of possible constraints include

  • Cooker can be constructed from readily available materials.
  • Cooker can be constructed using simple hand tools.

Examples of possible criteria include

  • Maximum temperature reached inside the cooker when it is placed in direct sunlight.
  • Volume of food that can be placed in the cooker.
  • Time required to cook a typical meal.

A possible variation on this section of the activity would be to have student teams independently develop criteria and constraints, and then through class discussion create a single set of criteria and constraints for the whole class. This would allow different teams to evaluate their prototypes using a class-wide standard.

Generate Ideas

Students generate ideas for the design of their solar cooker. For novice designers, it may be sufficient to use an ad hoc process to come up with two different concepts. For more advanced students, the process and tools described in this chapter may be appropriate.

Examples of possible design concepts include

  • A cardboard box with a clear plastic wrap top.
  • A cardboard box with a clear plastic wrap top plus foil covered cardboard reflector is to direct more sunlight into the box.
  • A cardboard box painted black inside with a clear hard plastic top.

Select a Design

Students use their constraints and criteria to select a design concept to use in creating their prototype. Advanced students should use the tools and process described in this chapter.

Build a Prototype

Students create a prototype of their selected design concept.

Test the Prototype

Students test their prototype to verify that it meets the constraints and perform the experiments necessary to determine how their design performs relative to the criteria.

Evaluate

Student teams present their designs and their processes to the class. Each student team’s processes are evaluated according to the rubric in Table 3 by the teacher and by the other students in the class. This evaluation is the basis of formative feedback to each team.

To implement the learning cycle, students could use this feedback to revise their designs and build a second prototype. This would emphasize the iterative nature of the design process.

Rubric to evaluate the overall design process as well as the steps in the design process.
Student Outcomes Strongly meets criteria Adequately meets criteria Minimally meets criteria Does not meet criteria
Recognize that design is a process. Gives detailed description of processes. Describe most steps of processes followed to design oven. Describe some steps of processes followed to design oven. Describes design without describing the design processes.
Quality of design process Evaluates quality of all steps and relates this to the quality of the resulting design. Evaluates quality of most steps and relates this to the quality of the resulting design. Evaluates quality of some steps and relates this to the quality of the resulting design. Does not evaluate the quality of any steps.
Apply each step: Criteria and constraints Identifies several criteria and constraints; criteria and constraints are properly formed. Identifies several criteria and constraints, most of which are properly formed. Identifies several criteria and constraints; some of which are properly formed. Does not identify several criteria and constraints; confuses criteria and constraints.
Apply each step: Generate ideas Decomposes the overall design problem, finds solutions to subproblems, and uses concept combination techniques. Uses one or two tools(brainstorming, problem decomposition, etc.) to develop several design concepts. Uses ad hoc processes to develop several design concepts. Only develops a single design concept.
Apply each step: Select a design Selects between design concepts using a formal tool with criteria and constraints. Uses a tool to select between concepts; selection reflects some criteria and constraints. Uses ad hoc processes to select between concepts; selection reflects some criteria and constraints. Does not use criteria and constraints to select between design concepts.
Apply each step:Prototype Tests the prototype to determine whether it meets all constraints and how it performs relative to all criteria. Tests the prototype to determine whether it meets most constraints and how it performs relative to most criteria. Tests the prototype to determine whether it meets some constraints and how it performs relative to some criteria. Test do not reflect criteria and constraints.

Solar Cooker Design Project Evaluation

The following exercise provides an assessment of students’ learning of the design process.

Theresa and Jack are designing a purification system for water that can be used in parts of the world where there is frequent flooding. They have a deadline and must work quickly because many parts of the developing world are suffering from severe flooding and people are getting sick drinking contaminated water. Jack feels that their first design is good and wants to build and ship the prototype to people in need. He does not want to waste time when lives are at stake. Theresa wants to look at several designs and then build and test a prototype. She thinks that they might even have to refine their prototype before it is ready for people to use. Jack argues that this process will take too much time. Use your knowledge of the design process to craft an argument that supports either Theresa or Jack.

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