Fair Tests to Improve a Design
Aligned to 3-5-ETS1-3 — Next Generation Science Standards.
What this lesson teaches
To find out what makes a design better, engineers run fair tests. A fair test changes only one thing at a time and keeps everything else the same, so you know exactly which change helped.
Worked example
Testing paper airplanes, you change only the wing size and throw them the same way from the same spot. Because only the wings differ, you can tell that bigger wings made the plane glide farther.
Practice questions
- Plan a fair test comparing two designs, listing the one thing you will change.
- Name three things you must keep the same to make the test fair.
- Run your test twice and explain what you would improve based on the results.
Watch the lesson
Every lesson comes with a video taught in English and Spanish — the same video the QR code in the printed workbook opens.
▶ Watch this lessonEn español
Pruebas Justas para Mejorar un Diseño
Para averiguar qué hace mejor un diseño, los ingenieros hacen pruebas justas. Una prueba justa cambia solo una cosa a la vez y mantiene todo lo demás igual, para saber exactamente cuál cambio ayudó.
Ejemplo: Al probar aviones de papel, cambias solo el tamaño de las alas y los lanzas de la misma forma desde el mismo lugar. Como solo cambian las alas, puedes saber que las alas más grandes hicieron que el avión planeara más lejos.
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