Learning Science · How experience becomes usable knowledge
What prior knowledge makes easier or harder
Use prior knowledge as a resource while detecting assumptions that obstruct a new idea.
Use the examples to connect this lesson with the earlier topics. No specialist equipment is needed.
Back to the chapterAfter reading, you can
- Explain facilitation and interference from knowledge
- Elicit a relevant starting model
A helpful expectation
Someone who knows how a library catalogue works may quickly understand a similar search system: enter a term, inspect matches and refine the query. Prior knowledge supplies expectations and reduces the amount that must be learned from scratch.
The same expectations can mislead. A new system may search only titles rather than full text. Repeating a familiar strategy without checking its scope can produce poor results. Knowledge helps when the old relationship applies and hinders when an old assumption is imported into a different case.
Find the starting model
Ask the learner to predict an outcome or explain a small case before teaching. The response reveals a usable idea and a possible mismatch. Avoid assuming that silence means no knowledge; the format or language may make existing knowledge hard to express.
When correcting a misconception, show the old prediction, a clear contrasting case and a better explanation. Simply adding the new fact may leave the old model active. The learner needs a reason to distinguish the cases and use the revised relationship.
Check conditions for use
Ask where the familiar method works and where it does not. Use examples that change a decisive condition rather than merely changing names. A changed task provides evidence about whether the learner revised the relationship or memorised an exception to the first example.
A misconception can persist alongside a correctly repeated definition. Ask for a prediction in a fresh case, not only the newly taught sentence. If the old expectation returns, compare the relevant conditions again. The revised idea becomes useful when it guides a choice in the face of a tempting old pattern.
Worked example
Multiplication and size
A learner says multiplication always makes a positive number larger. How can the quantity eight reveal the condition missing from that rule?
- Elicit the prediction for eight multiplied by two, then calculate sixteen. This preserves the valid pattern in early examples with positive factors greater than one.
- Ask for a prediction for eight multiplied by one half. Interpret the operation as taking half of eight: four. Compare four with eight rather than treating the result as an arbitrary exception.
- State the revised condition: for a positive starting quantity, a positive factor above one enlarges it, a factor of one leaves it unchanged, and a factor between zero and one reduces it. Check a fresh positive quantity and fraction.
The overgeneralisation needs repair, while the earlier whole-number examples remain valid. Eight times one half equals four because multiplication can scale a quantity down as well as up.
Multiplication changes scale
Try it yourself
Think through each question before opening the answer.
Why ask for a prediction before explaining?
Show the answer and reasoning
It makes the learner’s current expectation visible and supplies a clear point of comparison for the new explanation.
A prediction makes the active rule visible. Without it, a learner may repeat the correction while continuing to expect the old result when a new case appears.
What should a correction preserve?
Show the answer and reasoning
Valid earlier knowledge and the conditions under which it works, while repairing the overgeneralisation.
The useful earlier knowledge is conditional: multiplication by a positive factor greater than one enlarges a positive quantity. Teaching that boundary is more coherent than declaring every earlier example wrong.
Without doing a long calculation, is twelve multiplied by three quarters greater or less than twelve? Explain.
Show the answer and reasoning
Less than twelve; three quarters is a positive factor below one. The result is nine.
The revised relationship predicts the direction of change. Taking three of four equal parts of twelve also gives 3 × 3 = 9, checking the prediction.
What to carry forward
- Prior knowledge shapes interpretation.
- Elicit the relationship the learner expects.
- Teach the conditions that distinguish old and new cases.
References
Sources supporting the explanations and learning checks in this lesson.