Worked example
To test whether light affects seedling growth, which factor should differ?
Answer & why
Answer: the amount of light
Light is the factor named in the test question.
Grade 3 · Science
Plan a fair comparison
Change one tested factor while keeping other relevant conditions alike.
8 authored questions + worked example
Add to plan
All questions
All 8 authored questions for this skill.
Question 1
To test how wheel size affects distance, which factor should differ?
- the starting position
- wheel size
- the ramp height
- the car body
A hint
Identify the factor being tested and keep the comparison conditions consistent.
Answer & why
Answer: wheel size
Wheel size is the factor named in the test question.
Question 2
To compare dissolution at two temperatures, what should be the same?
- the water temperature
- the amount of substance added
- the time to dissolve
- the dissolution rate
A hint
Identify the factor being tested and keep the comparison conditions consistent.
Answer & why
Answer: the amount of substance added
Equal quantities help isolate the effect of temperature.
Question 3
To test whether light affects seedling growth, which factor should differ?
- the amount of water
- the amount of light
- the seed type
- the pot size
A hint
Identify the factor being tested and keep the comparison conditions consistent.
Answer & why
Answer: the amount of light
Light is the factor named in the test question.
Question 4
To compare two paper towels' absorbency, what should be the same?
- the amount of water applied
- the towel being tested
- the final result
- the amount absorbed
A hint
Identify the factor being tested and keep the comparison conditions consistent.
Answer & why
Answer: the amount of water applied
Equal water quantities make the comparison fairer.
Question 5
To compare ramp surfaces, what should be the same?
- the time to stop
- the ramp surface
- the distance rolled
- the starting height
A hint
Identify the factor being tested and keep the comparison conditions consistent.
Answer & why
Answer: the starting height
The surface should change while the starting height stays alike.
Question 6
To test whether wrapping affects cooling, which factor should differ?
- the starting water temperature
- the cup type
- whether the cup is wrapped
- the amount of water
A hint
Identify the factor being tested and keep the comparison conditions consistent.
Answer & why
Answer: whether the cup is wrapped
Wrapping is the tested factor.
Question 7
To compare growth of two seed types, which condition should be alike?
- the seed type
- the measured growth
- the ending height
- the watering schedule
A hint
Identify the factor being tested and keep the comparison conditions consistent.
Answer & why
Answer: the watering schedule
Changing water as well would confound the comparison.
Question 8
To compare magnet strength by lifted clips, what should be the same?
- the number of clips lifted
- the measured strength
- the magnet being tested
- the kind of paper clip
A hint
Identify the factor being tested and keep the comparison conditions consistent.
Answer & why
Answer: the kind of paper clip
Using the same kind of clip improves comparability.