The Design Process

In the Design Projects of the Materials World Modules, students follow a process of iterative design, as shown in the diagram. Through this process, students learn something about their initial design and then apply what they have learned as they work on a redesigned product. Because the design process is iterative, students get to apply what they learn in real and satisfying ways.

Moreover, real-world designs are often a compromise of performance and cost, wrapped in a package that will appeal to the consumer. When students work on the Design Projects, they can incorporate such design constraints as cost, ease of construction, durability, environmental impact, and customer appeal. For their final report or presentation, they can prepare advertising campaigns or marketing plans for their products, or suggest new markets and new applications for the products that they designed.

» State Design Goals
» Brainstorm and Select Best Option
» The Design Proposal
» Build the Design
» Test the Design
» Evaluate the Design
» Redesign

Each module culminates in a design challenge, a project in which students must apply what they have learned in the module to design a new material or object that makes use of materials from the module. For example, in the Composites module, students are challenged to design a prototype fishing pole based on a regular drinking straw.

The design challenge may be posed by the teacher (for instance, design a fishing pole) or be left to the students; each module includes both a teacher-directed and student-directed design project.

Once the topic is chosen, students and teachers collaborate to identify the constraints of the design. These criteria then lead to identification of the means of testing the design, which is usually based on tests performed in earlier activities.

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After the design task is sufficiently framed and guidelines or constraints established, students now have a clear idea of the specific object to design. But the means to accomplish that has been left up to the students.

Students are encouraged to spend some time brainstorming design ideas. Focusing on the product's goals as well as constraints will help them weigh the pros and cons of each design. Each student team should write down all possible ideas, even the ones that they decided won't work for some reason. They should start with their best option. The other design options may come in handy later to give the team further insight into something they didn't quite understand before.

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Once the design goals are established and students have had a chance to brainstorm, they are ready to propose designs that they believe will meet the design goals. The structure of the module encourages students to vary one variable across a number of prototypes so that they will be able to explore the effect of that variable on their design.

Students also make predictions about the effect their variable will have on their design, including how they expect their prototypes to perform.

Student design proposals typically include detailed information about how they will build the design, along with a materials lists. Once this is complete, building will commence.

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The process of building the design is, surprisingly, an iterative process. Students often make small changes to their design as they build, usually because once they can actually see how the design is taking shape, they realize that various aspects of the design will not work as well as they had imagined.

The net result of this tinkering process is that student designs often look little like those for the design proposal. Student predictions also often change during the building, because they start experimenting with their designs and learn more about how they perform. This is one reason why it is important for students to write down their predictions prior to starting to build their design.

Once students have built the set of variants based on their design, they are ready to test them.

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The method of evaluating different designs is usually based on the constraints that the design is intended to meet. Often this method can be decided by the students, although most teacher-directed design challenges in the modules suggest at least on possible testing method.

These tests are meant to mimic the behavior that the design will perform in the real world, in addition to measuring the inherent properties of the material. This focuses students on the relationship between these properties and real-world applications.

For example, in the fishing pole design project, students generate a list of characteristics of a fishing pole, such as flexibility, strength, weight, and cost. Students then decide which of these characteristics are the most important, and decide on a method to test each one.

Once students have interpreted the results of their tests and determined the performance of their designs, they can reflect on the relationship between their predictions and their results.

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Once students build, test, and evaluate their initial designs, they are asked to reflect on what they have learned from the first design in order to build a second design that will improve on the original. Support for reflection is embedded in the student journal in the form of questions for the students to consider.

Students should be able to identify variables they have found to be causal in the initial design, and create a design that maximizes (or minimizes) the effects of the known variables.

Students often present their results to the class and use class feedback to reflect on the pros and cons of their designs.

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Students then execute and test the redesign, and reflect on this design's performance in light of what they had learned about their earlier design.

This process may be repeated indefinitely, as students can continue to apply what they learned in earlier iterations while exploring new variables in the design space. Students may also take advantage of each other's design results, in effect exploring the design space in parallel.

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