Evidence Supporting Ideas · seed 1 · A4, ink-friendly. The answer key prints on its own page for grown-ups.

Checking the Evidence

Science · Scientific Inquiry · ages 9-11
Name ______________________   Date ____________

  1. A student measured only one plant, one time. Is that strong or weak evidence?

    • Strong, because it's a real measurement
    • Weak, because it's just one trial
    • Strong, because plants don't lie

  2. Which of these is a claim, not evidence?

    • Fish swim faster in warm water
    • The fish swam 10 cm in 5 seconds
    • The tank is 30 cm long

  3. Evidence can be used to show that a scientific idea is wrong.

    Circle one:   True   False

  4. Look at the chart. Ten plants got music, ten did not, and both grew to the same average height. Does this support the claim that music makes plants grow faster?

    No music5With music5
    • Yes, the music group is different
    • No, there's no real difference between groups
    • Yes, because 10 is a big number

  5. Ravi tests 10 plants with fertilizer and 10 without, keeping everything else the same, and repeats the test three times. Is this a fair test?

    • Yes, it compares groups and repeats trials
    • No, he needs only one plant
    • No, fair tests never repeat

  6. Which pair correctly matches a claim with its evidence?

    • Claim: 'The plant grew 4 cm.' Evidence: 'Water helps plants grow.'
    • Claim: 'Water helps plants grow.' Evidence: 'The watered plant grew 4 cm more than the unwatered one.'
    • A claim and its evidence are always the same sentence

  7. A scientist claims 'Adding salt makes ice melt faster.' She tests 20 ice cubes with salt and 20 without, under the same conditions, three separate times, and salted ice always melts faster. What can we say?

    • The evidence refutes the claim
    • The evidence is weak; more trials are needed
    • The evidence is strong and supports the claim

  8. Lily says: 'My one goldfish lived a long time in tap water, so tap water is safe for all fish.' What's wrong with her evidence?

    • Nothing, one goldfish is enough proof
    • It's based on a single case with no comparison or repeated trials
    • Goldfish evidence doesn't count for any claim
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Answer key

For grown-ups. Fold this page away before handing over the rest.

Checking the Evidence W1-mt_AstzvYDU2m-s1

  1. Weak, because it's just one trial · One trial isn't enough to be sure. Strong evidence needs multiple trials.
  2. Fish swim faster in warm water · A claim is what someone says is true. The other two are measurements, which count as evidence.
  3. True · Evidence that contradicts an idea refutes it, meaning it shows the idea doesn't hold up.
  4. No, there's no real difference between groups · Since both groups grew the same amount, the evidence does not support the claim. It actually refutes it.
  5. Yes, it compares groups and repeats trials · Comparing groups fairly and repeating trials is exactly what makes a test strong.
  6. Claim: 'Water helps plants grow.' Evidence: 'The watered plant grew 4 cm more than the unwatered one.' · The claim is the idea being tested. The evidence is the specific result that backs it up or not.
  7. The evidence is strong and supports the claim · Repeated trials with a fair comparison that consistently show the same result is strong evidence supporting the claim.
  8. It's based on a single case with no comparison or repeated trials · One goldfish is a single observation. Strong evidence would test many fish and compare conditions.
Worksheet · LightMySky