A fair test changes the factor being investigated while keeping other relevant conditions the same. Here the intended difference is wheel size. If a ramp or a cart’s mass also changes, that gives another possible explanation for the result. The recorded numbers are invented examples for checking the test design. The intended difference is wheel size. Check whether the ramps and masses also match before using the recorded result.
Engineering and scientific investigation · Discover & try
How can a comparison isolate one changed factor?
Reading level 2 of 5 · DevelopingChange
Word help
Independent variable
The factor deliberately changed.
Dependent variable
The outcome measured in a test.
Watch · Try · Explain
See how it works
The interactive activity is loading.
Invented cart outcomes illustrate experimental design. The shown variables do not cover every real influence, and the activity is entirely virtual.
What to look for
- Ramp and mass match, so the represented test isolates wheel size.
- The result now has another possible cause: the ramp changed too.
- Changing mass as well prevents a clean wheel-size conclusion.
Explain what you noticed
To compare light levels for two virtual plants, which plan best isolates light?
Keep this idea: Keep relevant conditions comparable so that the intended change can be interpreted.
Follow the sources
Source material checked 2026-10-29. Explanations and activities by Nepedia. Source links do not imply endorsement.
Keep following the idea
Next discovery →