Activity 1.7: Testing and Iterating

Activity Description

Students will develop their testing procedures, and start testing their prototypes. As they gather evidence about the performance using the catapults, they will iterate on their designs until they each create a cradle that successfully launches the projectile into the landing zone. They will record their process on the Testing Procedures student sheet, and results on their Prototype Testing student sheet.

Getting Started

Preparation Needed for the Activity:

Paper for recording results
Testing Procedures student sheet
Catapult Cradle Prototype Testing student sheet
Prototype cradles
Catapult set-ups for testing

Part 1 - Developing Testing Procedures: 20 - 30 min

Each requirement that was listed on the Understand student sheet will need to be tested.

Pose question: How do we test whether a prototype meets all the requirements?
On the Testing Procedure student sheet, they should write the first requirement that they want to record a test procedure for and give the test a name.
- Write the procedure for each test. Students can add multiple steps, as needed.
  - Note that a single test might give results for multiple requirements. For example, if a student included the requirements that the prototype must be made from an index card or card stock, and that the card must measure 5x8", these two requirements could be grouped in one test. Students could propose one test (e.g. Materials Test) that has two steps in the procedure--1) to measure the dimensions, and 2) to verify that it is an index card or card stock.
- Repeat until all of the requirements have tests associated with them.

A sample prototype net made of a simple line drawing. The central vertical rectangle intersects with three horizontal rectangles at different positions, each outlined and featuring dashed lines suggesting foldable sections.

Part 2 - Prototype #1 Testing: 30 - 45 min

Students will need multiple rounds of testing and modifications. They should record whether each shot passed or failed the test on a separate piece of paper. Chances are that their first prototypes won't work well, but students should record the final test results for this first prototype on their Catapult Cradle Prototype Testing student sheet, and calculate the Percent Success Rate. Students then modify their design to work better. These iterative modifications should be done based on evidence, but small modifications shouldn't be considered a new prototype. Large changes in design should be recorded as a new prototype, and students should record testing results on their Catapult Cradle Prototype Testing student sheet. Teams should test all of the prototypes that they made, but each student only records the results from their own prototypes.

Possible narrative
- We’ve gotten to prototyping and today we’ll get to testing in the design process. After testing, the next step is iterating. What does that mean? It means to make changes and try it again. In this class, you should iterate in an informed way, using the data that you collected to inform your next designs. It is important to update your Catapult Cradle Prototype Testing sheet each time you make and test a brand-new prototype. Give the new prototype a name and make a short note about the changes you made, and why.
As students conduct their performance tests using the catapults, they will quickly figure out if they are even in the correct ballpark. They should try at least 3 shots with a particular design before making substantial modifications. If it is clear that they won't reach 90% success, they should register that the trial failed.
After running each test, the students should indicate on the Catapult Cradle Prototype Testing student sheet whether the prototype passed or failed that test. (They can use text (P/F, or yes/no), or red and green colored pencils to indicate the results.)
Students can make minor modifications and conduct another trial using the same prototype. Or they can redesign and create a new prototype. Each new prototype should be entered onto their Catapult Cradle Prototype Testing student sheet, and they should run the tests again.
A sample prototype net is illustrated. In this example, the narrow rectangles will be tabs that wrap underneath to secure the cradle. The dotted lines represent the folds of the paper.

Part 3 - Iterating and Re-testing: 20 - 45 min

Remind students that each team needs to narrow their choice down to one working prototype as their final product. They will create their pitch and presentation using that prototype.
The teams should continue to iteratively redesign and test until they converge on one solution that works the best. Each team member should document the results for their own prototypes.
Make sure students are making informed decisions about their new designs using the data they’ve collected. Ask them why they made particular decisions.
When the team has converged on the best solution for the team, each individual should record that prototype and its test results on their student sheet.

Classroom Materials

1.7.1 Testing Procedure student sheet.pdf

1.7.1 - Testing Procedure (PDF)

1.7.2 Catapult Cradle Prototype Testing student sheet.pdf

1.7.2 - Catapult Cradle Prototype Testing (PDF)

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