Study guide: Material Design and Comparison
Compare paper model designs against a stated purpose.
Ideas to explain in your own words
- A material should suit the job. Our test cards provide four properties. Real samples vary; use only the supplied records and keep the reasoning tied to the intended function.
- Criteria describe what success looks like. Constraints limit materials, size or time. A solution must satisfy essential constraints before preferences can decide between it and another.
- Repeated tests reveal whether a result is consistent. A failed run should remain in the record. The supplied tests do not prove performance outside the stated conditions.
- Choose a change aimed at the observed failure. Changing everything at once makes it harder to identify the useful change. After revision, compare under matched supplied conditions.
Useful vocabulary
- strong
- holds the stated load
- criterion
- desired performance requirement
- consistent pass
- all supplied runs meet the goal
- widen
- cover an exposed edge
Watch your reasoning
- Check what strong and flexible each mean. They describe different clues.
- Check what criterion and material cap each mean. They describe different clues.
- Check what consistent pass and mixed each mean. They describe different clues.
A worked review example
Worked reference-card problem: a card states “holds the stated load”; a second states “bends around the stated corner.” The first fits strong and the second fits flexible. The reason is the described function or change, not the order of the cards or a favorite name. If their descriptions exchange places, their category labels exchange too. Keep the supplied descriptions attached to the correct case. Worked reference-card problem: a card states “desired performance requirement”; a second states “limit on supplied pieces.” The first fits criterion and the second fits material cap. The reason is the described function or change, not the order of the cards or a favorite name. If their descriptions exchange places, their category labels exchange too. Keep the supplied descriptions attached to the correct case. Worked reference-card problem: a card states “all supplied runs meet the goal”; a second states “some runs pass and some fail.” The first fits consistent pass and the second fits mixed. The reason is the described function or change, not the order of the cards or a favorite name. If their descriptions exchange places, their category labels exchange too. Keep the supplied descriptions attached to the correct case. Worked reference-card problem: a card states “cover an exposed edge”; a second states “support a bending span.” The first fits widen and the second fits reinforce. The reason is the described function or change, not the order of the cards or a favorite name. If their descriptions exchange places, their category labels exchange too. Keep the supplied descriptions attached to the correct case.
Make a practice plan
- Use an example from Choose evidence-based materials. Say what happens and point to the clue that helps explain it.
- Complete Distinguish criteria and constraints and correct the specific misconception in its feedback.
- Resolve a changed case from Read repeated model tests, then combine the four ideas in the transfer task.