Testing your design and improving it
Design & Technology · Key Stage 1 · The School
Testing is not the end
Making something is not the last step. Testing comes after. Does it actually do the job? A first test that fails is not the end of the project. It is real information, telling you exactly what to fix. Testing is part of the work.
Change one thing at a time
After a test fails, change only ONE thing. If you change three things at once and it works this time, you will never know which change actually fixed it. One change, one test. That is the rule that makes improvement real, not just lucky.
Testing against your criteria
Do not just ask "does it look finished?" Test it against each real requirement, one at a time. Does it hold the weight? Does it fit through the gap? Testing against the actual criteria, not against a feeling, is what makes a test genuinely useful.
Testing and fixing a wobbly bridge
A paper bridge must hold ten toy blocks without collapsing. Build it and test it. It collapses at six blocks. That is a real, useful result, not a failure to feel bad about. Change ONE thing: fold the paper into pleats along its length, and nothing else. Test again. It now holds nine blocks. Change one more thing: add a paper support underneath, and nothing else. Test again. It holds all ten. Two changes, two tests, and each one told you exactly whether it had actually worked.
Keeping a record as you go
Write down every test and every result, in order. Attempt one: six blocks. Attempt two: nine blocks. Attempt three: ten blocks. This short written record shows real progress, step by step, and is far more useful than trying to remember it all afterwards.