eduKate Learning Manual — Scientific Inquiry

Teaching goal: By the end of this manual, a learner should be able to tell the difference between evidence, inference, prediction and unsupported guessing, and explain what makes a scientific claim stronger or weaker.

Children guess all the time. Scientists do too.

The difference is that Science does not allow a guess to remain protected simply because it sounds sensible. A scientific idea must meet evidence.

This manual teaches a basic question that protects almost every other part of scientific reasoning:

What makes you say that?

1. The Big Idea: Evidence Can Be Checked

Evidence is information relevant to a question that can be observed, measured, recorded or otherwise checked.

• Evidence: “The temperature increased from 24°C to 31°C.”
• Inference: “The object probably gained heat from its surroundings.”
• Prediction: “If heating continues, the temperature may rise further.”
• Unsupported guess: “It became warmer because red objects always heat fastest.”

The last statement may sound scientific, but it needs evidence.

2. Evidence Is Relevant, Not Merely True

A fact can be true and still be irrelevant to the question.

Question: “Does changing the distance from a torch affect shadow size?”

• “The torch uses batteries.” — true but not useful evidence for the relationship being tested.
• “At 20 cm the shadow measured 14.8 cm; at 40 cm it measured 7.9 cm.” — directly relevant evidence.

Evidence quality begins with relevance.

3. Stronger Evidence Usually Has Better Method Behind It

Evidence becomes more trustworthy when:

• the observation is precise;
• the measuring method is consistent;
• important competing conditions are controlled;
• results are repeated or checked;
• the data are recorded honestly;
• the sample or range is appropriate for the claim;
• the conclusion does not exceed what was actually tested.

“I saw it once” may be evidence. It may simply be weak evidence.

4. Guesses Are Not Forbidden — They Must Be Exposed

A guess can be the beginning of inquiry.

Suppose a learner sees droplets on the outside of a cold cup and says, “Maybe the cup leaked.”

That is a possible explanation. Do not simply say “wrong”. Ask:

• What evidence supports the leak idea?
• What evidence might challenge it?
• Does the liquid level inside the cup fall?
• Do droplets still appear when the outside begins dry?
• Could condensation explain the observation better?

Science improves guesses by forcing them into contact with evidence.

5. Evidence Does Not Interpret Itself

Evidence must still be interpreted.

Two people may agree on the observation and disagree on the explanation. The next step is not to choose the more confident person. It is to compare which explanation better accounts for the available evidence and what additional evidence could distinguish them.

6. Worked Example: Circuit Fault

Observation: the bulb does not light.

• Guess 1: the cell is flat.
• Guess 2: the bulb is damaged.
• Guess 3: the switch is open.
• Guess 4: a connection is loose.

The observation alone does not select one explanation. More evidence is needed.

A strong learner asks what test or observation would separate the possibilities.

7. Evidence from Authority

Not every scientific question can be investigated directly in a classroom.

For established scientific knowledge, learners also use trustworthy sources such as official curriculum materials, scientific institutions, museums, universities and peer-reviewed research.

The same question still applies:

Why should I trust this source, and what evidence supports the claim?

8. Common Misconceptions — and Repairs

• “Evidence means anything I can say.” Repair: evidence must be relevant and checkable.
• “One observation proves the explanation.” Repair: one observation may fit several explanations.
• “A guess is always bad.” Repair: hypotheses often begin as ideas, but they must be tested.
• “If an adult says it, it is evidence.” Repair: authority can guide us to evidence but does not replace it.
• “Numbers are always stronger than words.” Repair: badly measured numbers can be weak evidence.
• “Evidence automatically tells us the cause.” Repair: causal interpretation depends on method and competing explanations.

9. Teach It: Evidence, Inference or Guess?

Read each statement and classify it.

1. The thermometer reads 30°C.
2. The water became warmer because the container absorbed heat.
3. I think the next reading will be 32°C because the previous readings were increasing.
4. The experiment failed because the plant dislikes Mondays.

Then ask what evidence would strengthen statements 2 and 3, and why statement 4 is unsupported.

10. Guided Practice: Rank the Evidence

Claim: a wider exposed water surface increases evaporation under similar conditions.

• A. “My friend says so.”
• B. One tray looked slightly lower after an hour.
• C. Three repeated comparisons using equal starting amounts showed greater measured water loss from wider trays.

C is stronger because the evidence is more directly measured, repeated and connected to a controlled comparison.

11. Independent Challenge: Ask for the Missing Evidence

Someone says, “This material is the best insulator.”

Write at least five questions you would ask before accepting the claim. Consider what was compared, what outcome was measured, whether conditions were kept similar, how many trials were done and what “best” means.

12. How an Adult Should Teach This

• Use “What makes you say that?” frequently.
• Ask what evidence would change the learner’s mind.
• Do not punish tentative ideas; require them to become testable.
• Separate confidence from evidence quality.
• Model changing your own explanation when evidence changes.

13. What Mastery Looks Like

• Beginning: treats plausible statements as facts.
• Developing: distinguishes clear evidence from unsupported guesses.
• Secure: asks for relevant evidence and identifies weak support.
• Strong: compares competing explanations and evidence quality.
• Advanced for Primary: can explain what additional evidence would change confidence in a claim.

14. Continue the Scientific Inquiry Sequence

• Previous: Drawing a Labelled Scientific Diagram
• Next: Repeating an Investigation to Check Results
• Recognising the Limits of a Simple Investigation

15. Trusted References

• Singapore Ministry of Education — Primary Science Teaching & Learning Syllabus
• Singapore Examinations and Assessment Board — PSLE Formats Examined in 2026

eduKate Learning Manual principle: A guess is allowed to enter Science. It is not allowed to leave as knowledge until evidence has done some work.