Challenge with a Counterexample

Worked classroom example

Across subjects

Worked example

A learner says all quadrilaterals are rectangles. A slanted parallelogram provides a case with four sides but without four right angles.

Use this example to make the language move visible. Select subject content appropriate to the class’s age and prior knowledge.

Teaching sequence

1. Speaker states a claim and reason.
2. Partner proposes a possible counterexample.
3. Both check whether the case meets the definition.
4. Speaker qualifies or defends the claim with a precise criterion.

Try it in your next lesson

Prepare

Use a general claim and a small case set. Choose a second example that checks the same language move without repeating the original answer.

Classroom task

Question a claim by offering a relevant case.

Check independent transfer

Ask learners to handle a fresh case without the original model.

Collect a response on fresh content. Note what was achieved without the model, partner or teacher prompt, then choose one next teaching step.

Teacher language

Teacher language

Does this case meet your rule, and if not, why not?

Respond to the learner

Identify one successful meaning or language choice. Ask about one gap, allow thinking time, then invite a revision. Check the revised move again on a fresh example.

Adjust support and challenge

Offer a brief model, useful vocabulary and partner rehearsal where needed. Keep the subject goal; reduce one prompt on fresh content and record what was independent.

Teaching this skill → · Age and language support →

More support

Offer thinking time, a small phrase bank and a clear listener role. Collect an individual explanation after paired rehearsal. Allow familiar-language notes or another response mode when checking subject understanding.

Greater independence

Change the content, evidence or audience. Remove the completed model and ask learners to explain a choice. Increase subject complexity only when it fits the curriculum and prior knowledge.

Choose the next step

If subject meaning is insecure, reteach the concept. If the concept is understood but the English is unclear, model one useful language relationship and invite a fresh response.