Bishan Science Tuition is a legacy title rebuilt around a learning problem that appears across Bishan Science tuition, Primary Science tuition Singapore, PSLE Science tuition, small-group Science tuition, open-ended Science questions, scientific keywords, concept mastery, experiments, graphs, application questions and answering techniques: children arrive in Science with powerful everyday intuitions, but everyday explanations do not always match the scientific models expected in school and examinations.
Strong Primary Science tuition should therefore help pupils convert ordinary experience into scientific observation, precise vocabulary, diagrams, system models, causal relationships, evidence-based explanations and testable predictions. A child may say a material is “bendy”, a plant “looks sad”, electricity gets “used up”, heat “goes inside”, or a heavy object “wants to fall”. These expressions are understandable starting points. The teaching job is not to mock them or merely replace them with fancy terms. It is to refine the underlying model until the child can reason accurately and communicate with scientific precision.
The revised 2026 PSLE Science paper makes this conversion important. Standard Science is one written paper lasting 1 hour 45 minutes, with 30 multiple-choice questions in Booklet A worth 60 marks and 10–11 structured questions in Booklet B worth 40 marks. SEAB’s assessment objectives include knowledge with understanding and the application of scientific knowledge through prediction, interpretation, evaluation and communication of explanations and reasoning. Pupils therefore need more than familiar experiences. They need scientific models that travel into diagrams, tables, graphs, experiments and unfamiliar situations.
Scope note: this article preserves its historical title and URL. It does not claim a current Bishan teaching location or affiliation. Its distinct educational job is intuition-to-model conversion: how a tutor can start from what a child naturally notices, make the hidden everyday model explicit, translate it into scientific language and representation, and then test whether the refined model works in new contexts.
Everyday intuition is not the enemy
Children spend years building informal explanations before formal Science lessons begin.
They notice:
- heavy objects can be hard to move;
- hot drinks cool down;
- plants wilt without care;
- magnets attract some objects;
- wet clothes dry;
- bulbs light when connected to batteries.
These observations are valuable.
The problem arises when the child turns one experience into an overly simple rule.
The teaching move: preserve the observation, refine the model
Suppose a pupil says:
“The metal spoon gets hot because metal likes heat.”
There is useful observation inside the sentence:
The spoon became warmer.
Do not discard that.
Refine the explanation toward heat transfer and material properties at the appropriate Primary level.
The conversion ladder
Everyday observation → ordinary explanation → scientific observation → scientific model → representation → prediction → new context
This ladder turns intuition into usable Science.
Stage 1: everyday observation
Ask what the child noticed.
Do not correct immediately.
Example:
“The water disappeared from the plate.”
This is a useful starting observation.
Stage 2: ordinary explanation
Ask:
“Why do you think that happened?”
The child may say:
“The sun drank it.”
“The wind blew it away.”
“It became air.”
These responses reveal the current model.
Stage 3: scientific observation
Improve precision.
Instead of:
“The water disappeared.”
Try:
“The amount of liquid water in the container decreased over time.”
Now the observation is less story-like and more measurable.
Stage 4: scientific model
Introduce the syllabus-appropriate process.
For evaporation, connect liquid water, environmental conditions and change of state appropriately.
The child receives a model that explains the observation better than “the water vanished”.
Stage 5: representation
Ask the pupil to show the model using:
- a labelled diagram;
- arrows;
- a table;
- a simple graph;
- a causal chain.
Representation makes the model visible.
Stage 6: prediction
Change one condition.
Ask what the model predicts.
If the pupil cannot predict, the model may still be verbal decoration.
Stage 7: new context
Use another object or situation.
The pupil should recognise the same scientific relationship.
This is transfer.
Everyday word: “bendy”
A child says:
“This plastic is bendy.”
Scientific refinement:
“The material is flexible.”
But do not stop at vocabulary.
Ask:
“How does flexibility make the material suitable or unsuitable for this use?”
The word becomes functional.
Everyday word: “see-through”
Refine to:
transparent, where appropriate.
Then compare transparent, translucent and opaque examples if within the pupil’s learning stage.
The scientific term should sharpen a real observed property.
Everyday phrase: “the plant is sad”
Preserve the observation:
leaves are drooping or wilted.
Remove the emotional inference.
Then ask which scientific conditions or processes could explain the observation.
Everyday phrase: “the bulb used the electricity”
This reveals a substance-like model of electricity.
Use circuit diagrams and system reasoning to replace the everyday story with a scientific model appropriate to Primary Science.
Everyday phrase: “heat entered the cup”
The phrase may point toward energy transfer but lacks direction and conditions.
Ask:
- Which object was hotter?
- Which was cooler?
- What happened to their temperatures?
- What scientific relationship explains that?
Everyday phrase: “heavy things fall faster”
This is a strong intuitive rule.
Rather than replacing it with another slogan, use controlled comparison and evidence at the appropriate syllabus level.
The child learns that visible weight alone does not automatically determine every motion outcome.
Everyday phrase: “plants eat from the soil”
This story is intuitive because roots are in soil.
Use plant-system diagrams to distinguish:
- water and mineral uptake;
- food production;
- transport;
- growth.
The system model replaces the everyday eating metaphor.
Everyday phrase: “the magnet pulls metal”
This may work for some familiar examples but becomes too broad.
Refine the category by testing magnetic and non-magnetic materials.
Scientific language should arrive after meaning
Vocabulary-first teaching can create pupils who sound scientific without understanding.
A better order:
- notice;
- compare;
- explain in ordinary language;
- refine the model;
- attach the scientific term;
- use the term in a new context.
The translation test
Ask pupils to translate both directions.
Everyday → scientific:
“It is bendy.” → “The material is flexible.”
Scientific → everyday:
“The material is a poor conductor of heat.” → “Heat does not pass through it easily compared with a good conductor.”
If pupils can move both directions, the vocabulary is meaningful.
The diagram test
A pupil who understands a system should be able to sketch the important parts and relationships.
Do not judge artistic quality.
Look for:
- relevant components;
- correct connections;
- direction of processes;
- labels that reflect the model.
The arrow test
Ask pupils to convert a sentence into arrows.
Example:
more available light → more photosynthesis under suitable conditions → more food produced → more growth
Every arrow should be explainable.
The object-to-graph test
Start with a real or imagined situation.
Ask:
“If we measured this over time, what might the graph look like?”
This converts an intuitive story into a representation.
The graph-to-story test
Reverse it.
Show a graph and ask the child to describe the physical story without explaining yet.
Then add the scientific mechanism.
The table-to-model test
Give a table.
Ask:
- What pattern is visible?
- Which everyday explanation comes to mind?
- Which scientific model fits best?
- What evidence would distinguish alternatives?
Scientific models are simplifications
A model does not contain every detail of reality.
It keeps the relationships useful for the question.
This is why a good model can travel across different surface contexts.
Model versus example
An example is one case.
A model is the relationship that explains many cases.
Pupils often confuse the two.
If they learned heat transfer using a cup, they may think the cup is part of the concept.
Change the object.
Model versus model answer
A model answer is a sentence or paragraph.
A scientific model is the underlying representation or relationship.
Pupils should be able to generate different correct wording from the same model.
Model versus mnemonic
Mnemonics can help retrieval.
They do not replace conceptual understanding.
If the pupil remembers an acronym but cannot predict a new case, the model is not yet secure.
Booklet A: intuition can make distractors attractive
MCQ distractors often match everyday intuition.
A child may choose the “obvious” answer because it feels familiar.
Teach:
intuition is a hypothesis; evidence is the test.
Before committing, compare the option with the scientific model and the question evidence.
Booklet B: ordinary language must become precise enough
Pupils do not need artificially complicated prose.
They need accurate scientific relationships.
Start from the child’s own explanation.
Then improve:
- the observation;
- the concept;
- the causal link;
- the vocabulary;
- the endpoint.
Example: upgrading an answer in stages
Stage 1:
“The plant is sad because it has no water.”
Stage 2:
“The leaves are wilted because the plant has less water available.”
Stage 3:
Add the relevant plant-water relationship expected by the question.
The tutor upgrades meaning without erasing the child’s starting observation.
The ordinary-language checkpoint
After a pupil writes a scientific answer, ask:
“Explain your sentence in everyday language.”
If the child cannot, the formal wording may be memorised.
The scientific-language checkpoint
After an everyday explanation, ask:
“Which Science word makes that idea more precise?”
This builds vocabulary from understanding.
Representations should agree
A pupil’s diagram, graph and written explanation should tell the same scientific story.
If the diagram implies one direction and the prose says another, there is a model inconsistency.
Model consistency audit
Ask:
- Does your diagram match your sentence?
- Does your graph prediction match your causal chain?
- Does your explanation fit the experiment result?
- Does the same model work in a new context?
Primary 3: preserve curiosity, refine language
P3 pupils should be encouraged to describe before being corrected into formal terms.
Use:
- real objects;
- sorting;
- comparison;
- simple measurement;
- prediction;
- sketching.
Scientific vocabulary grows from experience.
Primary 4: representations become more important
P4 pupils can move among:
- objects;
- diagrams;
- tables;
- simple graphs;
- complete explanations.
Primary 5: everyday intuition is tested harder
P5 topics introduce more situations where common sense can mislead.
Use prediction-before-evidence tasks to expose intuitive models.
Primary 6: model control under exam conditions
By P6, pupils should be able to:
- notice when intuition and evidence conflict;
- switch to the scientific model;
- read representations accurately;
- use precise vocabulary;
- transfer models to unfamiliar contexts.
Small-group model building
In a three-pupil group, ask each pupil to represent the same concept differently.
One draws.
One explains.
One predicts.
Then rotate.
The group sees that one model can appear in several forms.
The model comparison routine
Present two competing explanations.
Ask:
- What does each model predict?
- What evidence is available?
- Which model fits better?
- What further test would help?
This makes scientific modelling explicit.
Model revision should be normal
If new evidence does not fit, pupils should not feel embarrassed to revise.
Say:
“The model did not predict the evidence. What should change?”
This is scientific behaviour.
The intuition log
For selected topics, record:
| My first intuition | Evidence | Scientific model | New prediction |
|---|---|---|---|
| What felt obvious | What we observed | What explains it better | What the model predicts next |
The “sounds right” problem
Some wrong answers survive because they sound natural.
Science tuition should teach pupils to distrust sound alone.
Ask:
“What evidence makes it right?”
The “sounds scientific” problem
Other wrong answers contain impressive vocabulary.
Ask:
“Can you draw what that sentence means?”
If the pupil cannot, the language may be masking weak understanding.
The “diagram looks right” problem
A copied diagram may be visually accurate but conceptually empty.
Ask the pupil to change one condition and redraw the expected result.
The “graph looks strange” problem
If a graph contradicts intuition, do not force the graph to fit the expected story.
Read the evidence first.
Then reconsider the model.
A 90-minute intuition-to-model lesson
| Stage | Time | Purpose |
|---|---|---|
| Everyday prediction | 10 min | Expose intuition. |
| Observation/evidence | 15 min | Test intuition. |
| Model building | 20 min | Construct scientific relationship. |
| Representation | 15 min | Diagram/table/graph/arrow form. |
| Scientific language | 10 min | Attach precise vocabulary. |
| New-context prediction | 10 min | Test model transfer. |
| Independent explanation | 10 min | Confirm ownership. |
A twelve-week modelling progression
Weeks 1–2: expose intuitive models
Ask predictions and ordinary-language explanations.
Weeks 3–4: refine observations
Use measurement, comparison and evidence.
Weeks 5–6: build diagrams and causal models
Make relationships visible.
Weeks 7–8: translate representations
Move between words, diagrams, tables and graphs.
Weeks 9–10: vary contexts
Test whether models survive surface changes.
Weeks 11–12: timed application
Use MCQ and structured questions with reduced scaffolding.
When is the model secure?
The pupil can:
- describe the everyday observation;
- state the scientific observation precisely;
- explain the underlying model;
- represent it visually;
- use accurate vocabulary;
- make a prediction;
- revise when evidence conflicts;
- transfer the model to a new context.
Where this page sits in the eduKateYishun Science system
This page owns the intuition-to-scientific-model job. For misconception replacement after a wrong model has stabilised, use Bedok Science Tuition. For conditional rules and boundaries, use Parkway Parade Science Tuition. For evidence discipline, use Pasir Ris Science Tuition. For mechanism completeness, use Marine Parade Science Tuition.
The standard: make the invisible model visible
Everyday intuition gives children a starting point.
Science gives them a way to refine it.
Observe more precisely.
Represent the relationship.
Use evidence.
Adopt scientific language.
Predict.
Test.
Revise.
Transfer.
When pupils can do this, scientific vocabulary no longer sits on top of everyday thinking like decoration.
It becomes the language of a better model.
Current official references
The model-building casebook: six everyday intuitions worth refining
Case 1: “The cold came into the object”
Children often describe cooling as if “cold” were a substance entering something.
Do not begin with a vocabulary correction.
Ask:
- Which object started hotter?
- Which started cooler?
- What changed over time?
- What does the scientific model say about heat transfer?
The child’s everyday experience of “feeling cold” becomes a more precise model of energy transfer.
Case 2: “The plant drank food”
The child may combine eating, drinking and root uptake into one intuitive story.
Use a system diagram to separate:
- water uptake;
- mineral uptake;
- photosynthesis;
- food transport and use;
- growth.
The model becomes structured rather than metaphorical.
Case 3: “The battery pushes electricity into the bulb”
This story can help a child imagine activity in a circuit, but it may create later errors about current being used up.
Use complete-circuit representations and different arrangements to refine the model.
Ask what changes when the path is broken or restored.
Case 4: “The bigger object has more force”
Children may treat size as a universal explanation.
Separate:
- size;
- mass;
- force;
- movement;
- surface interaction.
Then test with examples where visible size is not the decisive variable.
Case 5: “Water disappears”
Everyday language is reasonable.
Science asks where matter goes and under what process.
Move from “disappears” to evaporation, then connect the process to conditions and evidence.
Case 6: “The magnet likes metal”
This child-friendly phrase gives the magnet intention and overgeneralises the material category.
Replace intention with interaction and test different materials.
Why ordinary language remains useful
Scientific vocabulary is not a separate language floating above experience.
Good teaching builds a bridge.
For example:
| Everyday phrase | Scientific refinement | Next reasoning step |
|---|---|---|
| bendy | flexible | How does flexibility affect suitability? |
| see-through | transparent | What function needs light to pass through? |
| gets hot easily | conducts heat well in the context | What temperature difference drives transfer? |
| plant looks sad | leaves are wilted/drooping | Which plant-water relationship could explain it? |
| water disappears | liquid water amount decreases through evaporation | Which conditions affect the process? |
The teacher should translate, not merely replace
When a pupil says “bendy”, reply:
“Yes, you noticed that it can bend. In Science, we call that property flexibility.”
The child sees continuity between observation and terminology.
This is better than treating ordinary language as evidence of failure.
Representation 1: objects
Concrete objects are powerful because they give pupils sensory evidence.
Use them for:
- material properties;
- magnetism;
- simple forces;
- circuits;
- measurement;
- classification.
But do not stop there.
Move from object to representation.
Representation 2: sketches
Ask pupils to sketch only the parts that matter.
This teaches abstraction.
A good scientific sketch is not an art contest.
It is a thinking tool.
Representation 3: labelled diagrams
Labels introduce scientific vocabulary and structure.
Ask pupils to explain why each label matters to the question.
This prevents decorative labelling.
Representation 4: arrows
Arrows show direction.
They are useful for:
- transport;
- energy transfer;
- causal sequences;
- life cycles;
- system relationships.
Every arrow should be explainable.
Representation 5: tables
Tables convert observations into organised comparison.
Pupils learn to separate variables and identify patterns.
Representation 6: graphs
Graphs compress relationships visually.
Ask pupils to move both ways:
data → graph
and:
graph → verbal explanation.
Representation 7: equations or symbolic statements where appropriate
Primary Science is not primarily equation-heavy, but simple symbolic relationships or arrows can help pupils see structure.
Keep them within curriculum expectations.
The representation-translation loop
Object → sketch → diagram → table → graph → explanation → prediction → new object
The learner should gradually move through several forms.
Why translation between representations matters
A pupil may understand a real experiment and still fail a diagram question.
Another may read a diagram but fail a graph.
The model needs to survive the representation change.
The “same model, four forms” exercise
Take one phenomenon.
Ask the pupil to:
- describe it in words;
- draw it;
- organise observations in a table;
- sketch a possible graph;
- explain the model;
- predict a changed case.
This is deep practice without requiring six unrelated worksheets.
The “two models, one observation” exercise
Present one observation that could have more than one explanation.
Ask pupils to propose two models.
Then ask:
“What evidence would distinguish them?”
This teaches that a scientific model must answer to evidence.
The “one model, two predictions” exercise
Take one scientific model and change two different conditions.
Ask what the model predicts in each case.
The pupil learns the model as a generator of expectations.
The “model failure” exercise
Show evidence that does not fit the pupil’s current model.
Ask:
- What did the model predict?
- What actually happened?
- Which assumption may be wrong?
- How should the model be revised?
This builds intellectual flexibility.
Models should become more precise with age
A P3 model can be simple.
A P6 model should usually contain more relationships and conditions.
Do not expect the same explanatory precision from every level.
P3 modelling example: material properties
Start with objects.
Observe:
- flexibility;
- transparency;
- waterproof behaviour;
- strength in simple comparisons.
Then connect property to use.
P4 modelling example: plant structures
Move from labelled plant diagram to function.
Ask what happens if one structure cannot perform its role.
P5 modelling example: electrical system
Move among:
- real circuit;
- circuit diagram;
- system explanation;
- changed arrangement;
- prediction.
P6 modelling example: forces and environmental interactions
Require pupils to identify which objects interact, what evidence shows the effect, and how the model predicts a new situation.
Everyday intuition and MCQ distractors
Distractors often work because they feel sensible.
Examples:
- large object = heavy;
- metal = magnetic;
- more batteries = always brighter;
- water outside cold cup = leaked water;
- plant roots = food intake.
Ask pupils to identify the intuitive story behind the distractor.
Everyday intuition and open-ended language
Pupils should not be punished for starting from ordinary language in learning.
But examination answers need scientific precision.
Build a two-stage routine:
- say it naturally;
- translate it scientifically.
Example: natural to scientific
Natural:
“The metal gets hot easily.”
Scientific:
“The metal conducts heat well, so heat is transferred through it more readily under the stated conditions.”
The exact wording should fit the question.
Example: scientific back to natural
Scientific:
“The material is flexible.”
Natural:
“It can bend without breaking easily.”
If pupils can move both ways, the word is understood.
Model-building and retrieval
Ask pupils to redraw a model from memory.
Examples:
- plant-water pathway;
- simple circuit;
- water-cycle sequence;
- causal chain for heat transfer.
Then compare with notes.
Model-building and transfer
After the model is secure, change the object or representation.
The pupil should recognise the same structure.
Model-building and explanation quality
A strong model makes writing easier.
The child no longer searches memory for a perfect sentence.
The child describes the model accurately.
Model-building and self-correction
Ask pupils to check whether their written answer agrees with their diagram.
Contradictions reveal misunderstanding.
Model-building and misconception repair
A misconception is often an alternative model.
Do not fight it only with vocabulary.
Compare predictions.
Use evidence.
Replace the model.
Model-building and fair tests
Experiments test relationships between variables.
A model tells the pupil what relationship is expected.
A fair test tells the pupil whether the evidence can isolate it.
Model-building and uncertainty
When a pupil is unsure, ask:
“What model would explain the evidence best?”
This is more productive than guessing a keyword.
The model notebook
For major concepts, use one page with:
- core diagram;
- key relationships;
- important vocabulary;
- common misconception;
- one prediction;
- one unfamiliar application.
This is more useful than a page of isolated definitions.
The model quality checklist
A good Primary Science model should:
- fit the evidence;
- use syllabus-appropriate concepts;
- make predictions;
- work across more than one example;
- have clear boundaries;
- be explainable by the pupil.
Small-group model comparison
Three pupils may draw three versions of the same system.
Compare them.
Which one includes the relevant parts?
Which one has the direction wrong?
Which one includes unnecessary decoration?
The discussion improves model quality.
Model-building under time pressure
During revision, train quick representations.
A three-arrow causal chain may be enough.
A simple sketch may prevent a long reading error.
The model should become efficient, not elaborate.
The five-minute model drill
Choose one concept.
In five minutes:
- draw it;
- label it;
- state the key relationship;
- give one example;
- predict one changed condition.
This is compact retrieval and transfer practice.
The parent role
Parents can ask model questions without teaching the whole topic:
- What do you think is happening?
- Can you draw it?
- What evidence supports your drawing?
- Which Science word describes that relationship?
- What would happen if this condition changed?
These prompts encourage the child to externalise thinking.
What parents should avoid
Avoid immediately supplying the scientific word.
Let the child describe the idea first.
Otherwise vocabulary can replace thinking.
The final model stress test
Choose a concept the pupil believes is secure.
Give:
- one object-based question;
- one diagram;
- one graph or table;
- one prediction;
- one unfamiliar application.
Ask the pupil to explain how all five connect to the same underlying model.
If the model survives representation changes, the learning is becoming portable.
The deeper educational value of model building
Scientific models give pupils a way to improve intuition rather than abandon it.
Children continue to use experience.
They simply learn to inspect experience more carefully.
They measure.
They represent.
They compare.
They test.
They revise.
That is how everyday noticing becomes scientific reasoning.
A practical model-conversion clinic
Take one answer from the child’s schoolwork that sounds reasonable but is not scientifically precise. Work through four versions rather than simply crossing it out.
Version 1: preserve the child’s own words
Write exactly what the pupil meant.
Example:
“The plant is droopy because it is thirsty.”
This matters because the pupil should see that the starting intuition contains useful information.
Version 2: separate observation from story
Rewrite only the observation:
“The leaves are drooping.”
Now the statement is evidence rather than interpretation.
Version 3: build the scientific model
Ask which plant-water relationship explains the observation. Draw the relevant pathway or causal chain. Identify what the question gives and what the model predicts.
Version 4: write the examination answer
Convert the model into precise, concise scientific language suited to the command word and mark allocation.
This clinic teaches pupils that scientific writing is the final stage of thinking, not the beginning.
Why model conversion helps weaker writers
Some children struggle with Science because they are asked to produce polished scientific sentences before they have organised the underlying model.
Allow them to:
- say the idea;
- draw the idea;
- connect the arrows;
- then write the idea.
This reduces language load while preserving scientific demand.
Why model conversion helps strong writers
Strong writers can hide weak Science inside fluent prose.
Ask them to draw the model behind the paragraph.
If the arrows do not make sense, the elegant language is not enough.
The model-first correction routine
When an answer is wrong:
- do not show the model answer yet;
- ask the pupil to draw what they thought was happening;
- compare the drawing with the evidence;
- repair the relationship;
- attach accurate vocabulary;
- rewrite;
- test a new context.
This turns correction into conceptual work.
The final representation audit
For one major concept, ask the pupil to produce four forms from memory:
- a two-sentence explanation;
- a labelled sketch;
- a causal arrow chain;
- a prediction for a changed condition.
Then ask whether all four tell the same scientific story.
If they do, the model is likely coherent.
If one representation contradicts another, investigate the disagreement rather than memorising another answer.
The final standard for Bishan Science Tuition
A pupil has moved beyond everyday intuition when ordinary observations can be translated into scientific models and back again without losing meaning.
The child can say what was noticed, represent what is happening, name the relevant concept, explain the relationship, predict a new case and revise when evidence disagrees.
That is more useful than sounding scientific.
It is scientific understanding becoming operational.
The final model-conversion check
Choose one everyday statement such as “the water disappeared”, “the material is bendy” or “the bulb used the electricity”. Ask the pupil to convert it into four forms: a precise observation, a scientific term or model, a representation, and a prediction.
If the four forms agree, the intuition has been successfully reorganised into scientific understanding. If the pupil can use the same model in a new context, the conversion has transferred beyond the original example.
This is the desired progression: ordinary experience remains the starting point, but evidence and scientific modelling become the tools that decide what the experience means.
The two-way model test
A secure model should work in both directions. From a real-world situation, the pupil should be able to identify the scientific model. From the scientific model, the pupil should be able to generate a realistic example.
Try this with flexibility, heat transfer, circuits, evaporation, plant systems and forces. If the child can translate only from textbook language to a memorised example, understanding is still narrow. If the child can move between observation, model, representation and new example, the knowledge has become more flexible.
One final modelling check
Ask the pupil to explain a familiar phenomenon without using the usual textbook keyword. Then ask for the precise scientific term, a simple representation and one new prediction.
If meaning survives without the keyword and precision improves when the keyword is added, vocabulary is serving the model rather than replacing it. If the pupil can then transfer the same model to a different example, the scientific understanding is becoming portable.
Final rule: a scientific model is secure when the pupil can move from experience to representation, from representation to explanation, and from explanation to a fresh prediction without losing the underlying relationship.
The pupil should also be able to explain why the scientific version is better: it identifies observable quantities and relationships, avoids unsupported intention or metaphor, and can be tested against new evidence.