Plan Fair Tests
Grade 4 - Science - Building Confidence
Fair-test plan: for the problem "a warning code must send three messages with light," which test would compare solutions clearly?
- spray each package five times and check the seeds
- add washers one at a time until the bridge bends
- pour the same amount of water on each roof model
- ask a partner to read the flash cards without hints
Which variable should stay the same while testing designs for "a paper bridge must hold 20 washers"?
- uses only two sheets of paper and tape
- the conclusion after testing
- keep the folded beams and strengthen the center span
- fold the paper into beams before taping it
Evidence: the side-channel roof kept the doorway dry twice. Which improvement follows from the data?
- tilt the fabric to block afternoon Sun too
- add longer pauses between messages
- make the side channel deeper
- keep the folded beams and strengthen the center span
Why should engineers repeat a test for "a paper bridge must hold 20 washers"?
- repeating removes the need for measurements
- repeated trials make the evidence more reliable
- data should be ignored after one test
- each trial should use a different criterion
Which data table heading best fits a fair test for "a model roof must drain rainwater away from a doorway"?
- title only
- weather, lunch choice, recess game
- unrelated source, spelling score
- solution tested, measurement, result
Fair-test plan: for the problem "a wind barrier must stop soil from blowing away," which test would compare solutions clearly?
- measure temperature in sun and under the cover at noon
- pour the same amount of water on each roof model
- ask a partner to read the flash cards without hints
- run a fan for one minute and measure sand moved
Which variable should stay the same while testing designs for "a model roof must drain rainwater away from a doorway"?
- slope the sheet toward a side channel
- make the side channel deeper
- the conclusion after testing
- uses one plastic sheet and four straws
Evidence: folded beams held 24 washers while flat paper held 9. Which improvement follows from the data?
- tilt the fabric to block afternoon Sun too
- reduce gaps between the sticks
- keep the folded beams and strengthen the center span
- seal the envelope edges with tape
Why should engineers repeat a test for "a wind barrier must stop soil from blowing away"?
- repeating removes the need for measurements
- each trial should use a different criterion
- repeating proves the first idea was perfect
- repeated trials make the evidence more reliable
Which data table heading best fits a fair test for "a wind barrier must stop soil from blowing away"?
- weather, lunch choice, recess game
- solution tested, measurement, result
- unrelated source, spelling score
- title only