Fair testing (age 8+)
Plan and carry out fair tests in which variables are controlled and failure points are considered to identify aspects of a model or prototype that can be improved
What a learner can do afterwards
- Plan a fair test of a prototype with clearly identified variables to control
- Carry out the test and identify failure points or weaknesses in the design
- Propose specific improvements based on test results and retest
1 · Read
A fair test compares two designs by changing only one thing at a time. That one thing is called the variable. Everything else, like the tools you use and how you measure, stays exactly the same. This way, you know what really caused the result you see.
Mia built two paper boats to find out which sail shape catches more wind. She used the same fan, the same water, and the same starting spot for both boats. She only changed the height of the sail. Boat A had a short sail and moved 6 steps. Boat B had a tall sail and moved 9 steps. Because the sail was the only thing that changed, Mia knew the taller sail made the boat go farther.
While you test, watch closely for failure points, the moments when the prototype breaks, jams, or does not work the way you planned. Write these down, even if the test still finishes.
Use what you found to make one specific change, then run the same fair test again to see whether that change actually helped. A failure in one spot is information about that spot, not a verdict on the whole design, so fix the spot rather than starting over. Fix it before you make the test harder, too: repeating a test you already failed, only tougher, tells you nothing you did not already know.
Change one thing, watch closely for what breaks, then fix that one spot and test again.
2 · Watch
Take it off screen
Where it sits
This opens up
Where this leads
8 questions wait behind this lesson, each with its answer explained. Every answer feeds the sky: stars light as they are learned, and dim when it is time to come back.