Skill companion: Questions, Hypotheses and Models (Year 9)

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Skill companion · Year 9 Science Inquiryseegongsik /au

Questions, Hypotheses and Models: a skill companion

A small set of reusable sheets that grow one inquiry skill: turning a pattern into an investigable question, building a hypothesis into an explanatory model that says why, predicting the shape of the relationship it leads to, and testing that shape so the model can be refined. Print the scaffolds once and slot them into the science lessons you already teach.

AC9S9I01

develop investigable questions, reasoned predictions and hypotheses to test relationships and develop explanatory models

What a skill companion is

Inquiry skills are not a topic of their own. They grow inside the science units a class teaches all year, such as Body Systems, Reproduction, The Carbon Cycle, Wave and Particle Models, Conservation of Energy, The Atom and Chemical Equations. So this pack is not a full term of lessons. It is three reusable scaffolds, a map of where they fit, and a short stand-alone lesson for teaching the skill on its own first.

Start here: five minutes

Read the pairing map on the next page: it shows which scaffold fits which science lesson.
Print the model builder and the relationship sheet, one each per student, whenever a lesson starts from a pattern.
Cut out the cards once. They are reused all year, and the blank cards fit any topic.
Open the free interactive unit on your board when you want a worked example of the skill.
Run the one-page mini-lesson first if you want to teach the skill before folding it into a topic.

The step up from Year 8

In Year 8 students kept the hypothesis, an explanation drawn from a model, apart from the prediction it leads to. In Year 9 the hypothesis grows into an explanatory model: a chain of cause and effect that predicts not only which way a result goes but the shape of the relationship, such as a straight line through zero or a curve that levels off. Testing that shape does more than pass or fail the idea: where the results drift from it, the model is refined.

On the board

This pack is the printable half of a free interactive unit. On screen, students press “Let it vary” until every line reads “Kept the same” in “Frame the question: change only the jacket thickness”, switch “See the relationship between thickness and cooling” to “Line graph”, click the reading that breaks the trend in “Spot the trial to recheck”, and sort statements with “Hypothesis” and “Not a hypothesis” in “Hypothesis or just a guess?”.

seegongsik.com/au/y9/inquiry/AC9S9I01

Aligned to the Australian Curriculum V9 (AC9S9I01). This pack is original material from seegongsik, independently produced and not endorsed by ACARA. Curriculum content descriptors are (c) ACARA, licensed under CC BY 4.0. Free to print and use in class.

Where the skill fitsPairing map

Slot the skill into your science lessons

The same skill fits into every science unit. This map shows a pattern students can notice in each Year 9 topic, an investigable question about it, the model that would explain it, and which scaffold to reach for. You do not run these as extra lessons; you fold them into the science you teach.

When you teach	Pattern students can notice	Investigable question	The model behind it	Scaffold
Body Systems and Negative Feedback (AC9S9U01)	After a run, the heart rate falls back to its resting rate	How does the time spent skipping affect how long the heart rate takes to return to resting?	Negative feedback: a change is detected and the body responds to undo it	Model builder
Reproduction in Animals and Plants (AC9S9U02)	Cuttings from the same plant grow roots at different rates	How does the number of leaves left on a cutting affect the number of roots after two weeks?	Leaves make the sugars new roots are built from, but they also lose water	Model builder, then the cards
The Carbon Cycle (AC9S9U03)	Indicator around a leaf in a sealed tube changes colour in the light and in the dark	How does the distance from a lamp affect the colour of the indicator after an hour?	Photosynthesis takes in carbon dioxide in the light; respiration gives it out all the time	The relationship sheet
Wave and Particle Models of Energy (AC9S9U04)	A pulse runs faster along a tightly stretched slinky	How does how far a slinky is stretched affect the time a pulse takes to cross it?	Each coil pulls on the next, and a tighter coil passes the disturbance on sooner	Model builder
Conservation of Energy and Efficiency (AC9S9U05)	A dropped ball never bounces back to the height it fell from	How does the drop height affect the bounce height of a tennis ball?	The ball keeps a share of its energy at each bounce; the rest becomes heat and sound	The relationship sheet
The Atom and Radioactive Decay (AC9S9U06)	When every die that shows a six is removed, fewer are removed each throw	How does the number of throws affect the number of dice left?	Each die, like each nucleus, has the same chance on every throw	The relationship sheet, then the cards
Chemical Equations and Conservation of Mass (AC9S9U07)	An open cup of vinegar gets lighter as bicarbonate of soda fizzes in it	How does the mass of bicarbonate of soda added affect the mass the open cup loses?	Atoms rearrange into carbon dioxide, which escapes; no atoms are lost	The cards, then the model builder
Any science topic	A pattern a student spots for themselves	The student names what to change, what to measure and what to keep the same	Any model the class has met	Model builder first

Safety: skipping is light exercise; let any student with a health condition time and record instead. Lamps stay away from water. An adult fills any cup of warm water from the hot tap, never from a kettle.

The three moves, and the picture that backs each one

Change one variable, measure one, keep the rest the same: “Frame the question: change only the jacket thickness”.
Read the shape of the relationship, and recheck a reading that breaks it: “See the relationship between thickness and cooling” and “Spot the trial to recheck”.
Tell a hypothesis that proposes a mechanism from a guess: “Hypothesis or just a guess?”.

Scaffold 1 · Model builderOne per student

From a pattern to an explanatory model

NameClassDate

A hypothesis becomes an explanatory model when it gives a chain of cause and effect: why the pattern happens, step by step. The chain predicts the shape of a relationship, and a test of that shape can support the model or show where it needs refining.

What I noticed

Draw it or write it

My investigable question

How doesthe variable I changeaffectthe variable I measure?

The variables

Independent variable the one I change
Dependent variable the one I measure, and its unit
Controlled variables at least three I keep the same

My explanatory model: the chain of cause and effect

The cause (what I change)

→

In between (the model)

→

The effect (what I measure)

The shape my model predicts

□ rises in step: a straight line through zero

□ rises, then levels off

□ falls by the same share each step

□ falls, then levels off

□ something else: ______________________________

Prediction, test and refinement

My prediction, with a number if I can:

A result that would count against my model:

If the results only partly fit, I would refine the model by

My model says why, as a chain of cause and effect.Yes □Not yet □

Teacher note: a middle box that only repeats the question (“more layers make it cool slower”) is a prediction, not a model. Ask what is happening to the particles, the cells or the energy in between.

Scaffold 2 · Test and refine a modelOne per student

Does the relationship have the shape the model says?

NameClassDate

A model predicts the shape of a relationship. Testing that shape can support the model, and where the results drift away from it, it shows how the model should be refined.

A. The model, the prediction and the results

Class 9B’s model: when a ball lands it squashes, and it keeps the same share of its energy to rise again; the rest becomes heat and sound. Their prediction: the bounce height is the same fraction of the drop height at every height, so the points lie on a straight line through zero. They dropped the same tennis ball onto the same hard floor from six heights, three times each, and recorded the middle bounce.

Drop (cm)	Bounce (cm)	Bounce ÷ drop
25	18
50	36
75	53
100	70
150	102
200	128

The dashed line is the first model: the share kept at the lowest drops, carried on to every height.

B. Test the shape

Fill the last column to two decimal places. Does the share stay the same, as the model says? Where does it change?

C. Predict

From 125 cm (inside the tested heights) I predict

From 300 cm (outside them) I predict

Which prediction am I surer of, and why?

D. Refine the model

Change the model so that it explains all six results. Then describe a test that could check your change.

After the test: did the results support the first model?Yes □Partly □No □

Scaffold 3 · Question, hypothesis or prediction cards (cut out)Reuse all year

Question, hypothesis or prediction?

Cut out the cards. Lay down the three grey heading cards, then sort the statement cards under them. On the blank cards, write a prediction that one of your hypothesis cards leads to.

Investigable questionAsks how one variable affects another, so a test can answer it.Heading

HypothesisProposes why it happens: a chain of cause and effect from a science model.Heading

PredictionSays what we will observe or measure, without saying why.Heading

Sweat takes heat from the skin as it evaporates, so on a hot day the body sweats more and its temperature is brought back down.Card A

How does the time spent skipping affect how long the heart rate takes to return to resting?Card B

A pulse will cross a tightly stretched slinky in less time than a loose one.Card C

How does the number of layers of bubble wrap affect how far warm water cools in 10 minutes?Card D

A tighter slinky pulls back harder on each coil, so each coil passes the disturbance on sooner.Card E

Leaves make the sugars that new roots are built from, so a cutting with more leaves can grow more roots.Card F

If more bicarbonate of soda is added to the open cup of vinegar, then the cup will lose more mass.Card G

Each die has the same chance of a six on every throw, so the same share of the dice left is removed each time, as with the nuclei in a decaying sample.Card H

How does the distance of a lamp affect the colour of the indicator around a leaf in a sealed tube?Card I

In a reaction the atoms only rearrange, so carbon dioxide made in an open cup escapes into the air while the atoms in a balloon-capped bottle all stay inside.Card J

The bounce height will be about three-quarters of the drop height at every height we try.Card K

How does the number of dice affect how many throws it takes until half are removed?Card L

A prediction from hypothesis card ___:

Write your own

A prediction from hypothesis card ___:

Write your own

A prediction from hypothesis card ___:

Write your own

Teacher note: the piles are not the same size, and an if-then sentence is not always a hypothesis. The answer sheet lists which card is which, and why.

Mini-lesson · Teacher planAbout 30 minutes

A model that predicts a shape

Use this stand-alone lesson to teach the skill on its own, before you fold it into a science topic. Cups of warm water wrapped in 0, 1, 2 and 3 layers of paper towel give the class a pattern within ten minutes. The particle model of trapped still air supplies the explanatory model, and the model predicts the shape: each layer should cut the heat loss by about the same share, so the curve levels off rather than falling in a straight line.

We are learning to

build a hypothesis into an explanatory model: a chain of cause and effect from a science model,
predict the shape of a relationship from the model, not only its direction,
decide whether results support the model, and how to refine it if they only partly fit.

Success criteria

I can write the chain of cause and effect for the paper towel layers.
I can say which shape my model predicts and check it against our results.

You need

for each group: four cups of the same kind, paper towel and rubber bands to wrap 0, 1, 2 and 3 layers, a measuring jug, a thermometer and a stopwatch; warm water from the hot tap (an adult fills the cups; not from a kettle),
the model builder (scaffold 1), one per student, and the cards from scaffold 3, one set per table. Wipe up spills straight away.

Lesson flow (about 30 minutes)

5 min	Set it going Groups wrap the cups, the adult pours 150 mL of warm water into each, and groups read the starting temperatures. Ask: “Which cup will cool most in ten minutes? Why do you think so?”
10 min	Build the model While the cups cool, each student fills the model builder. Show the board (see the box). Ask: “What is happening between the water and the room? Which box of your chain says that?”
5 min	Sort the cards Tables sort the cards under the three heading cards. Ask: “Card G says “if … then”. Why is it still not a hypothesis?”
10 min	Read the shape At ten minutes, groups read the final temperatures, work out each drop and how much each new layer saved. Ask: “Did each layer save about the same share, as the model said? What would ten layers do?”

Running it shorter? Stop after the model builder, and pick up the cups and the cards in your next science lesson.

On the board

For a worked example, open the unit and press “Let it vary” on each line of “Frame the question: change only the jacket thickness” until all three read “Kept the same”. Then switch “See the relationship between thickness and cooling” from “Bar chart” to “Line graph” and ask what shape the line makes.

seegongsik.com/au/y9/inquiry/AC9S9I01

Watch for these ideas

A model that only repeats the pattern, such as “more layers keep it warmer because they make it cool slower”.
Expecting every relationship to be a straight line.
Throwing a model away at the first result that does not fit, instead of refining it or repeating the trial.

Make it easier, make it bigger

Easier: give the chain frame “More layers trap more …, which … heat poorly, so …” and the shapes to choose from.
Bigger: predict the drop with 5 layers from the shape, then test it and see how close the prediction came.

Answers and look-fors

The next sheet has the card key, the worked bounce results, a model chain and prediction for each Year 9 topic, and a quick three-level guide.

Answers · For the teacherModel responses

Answers and look-fors

Question, hypothesis or prediction cards

Card	Statement	Pile	Why
A	Sweat takes heat from the skin as it evaporates, so on a hot day the body sweats more and its temperature is brought back down.	Hypothesis	A negative feedback chain: a change, a response, the change undone.
B	How does the time spent skipping affect how long the heart rate takes to return to resting?	Investigable question	One variable changed (time skipping), one measured (recovery time).
C	A pulse will cross a tightly stretched slinky in less time than a loose one.	Prediction	A time to measure, but no reason; card E explains it.
D	How does the number of layers of bubble wrap affect how far warm water cools in 10 minutes?	Investigable question	Layers changed, temperature drop measured.
E	A tighter slinky pulls back harder on each coil, so each coil passes the disturbance on sooner.	Hypothesis	Explains the pulse speed with how the coils push and pull on each other.
F	Leaves make the sugars that new roots are built from, so a cutting with more leaves can grow more roots.	Hypothesis	Explains root growth with photosynthesis in the leaves.
G	If more bicarbonate of soda is added to the open cup of vinegar, then the cup will lose more mass.	Prediction	An if-then sentence with no reason: a prediction, not a hypothesis. Card J explains it.
H	Each die has the same chance of a six on every throw, so the same share of the dice left is removed each time, as with the nuclei in a decaying sample.	Hypothesis	A model of chance that explains why the number left falls by the same share.
I	How does the distance of a lamp affect the colour of the indicator around a leaf in a sealed tube?	Investigable question	Distance changed, indicator colour observed.
J	In a reaction the atoms only rearrange, so carbon dioxide made in an open cup escapes into the air while the atoms in a balloon-capped bottle all stay inside.	Hypothesis	Explains the mass lost from an open cup with the conservation of atoms.
K	The bounce height will be about three-quarters of the drop height at every height we try.	Prediction	A number to check, with no reason.
L	How does the number of dice affect how many throws it takes until half are removed?	Investigable question	Number of dice changed, throws counted; the model on card H says it should not matter.

A blank card at standard, from card F: ‘Cuttings with four leaves will grow more roots in two weeks than cuttings with one leaf.’

Testing and refining a model: the bounce

Bounce ÷ drop: 0.72, 0.72, 0.71, 0.70, 0.68, 0.64. The share stays at 0.72 for the lowest drops, as the first model says, then slips as the drop grows, so the highest points fall below the dashed line: the results support the model only partly. From 125 cm, between the readings at 100 and 150 cm, about 86 cm is a confident prediction. From 300 cm the first model gives 0.72 × 300 = 216 cm, but the slipping share says at most 0.64 × 300 = 192 cm, and probably less: a less sure prediction, since nothing was tested that high. A refined model: the ball keeps a smaller share of its energy when it lands faster, because it squashes more and the air pushes on it harder at speed. Tests: drop it from 250 and 300 cm and check that the share keeps falling, or compare a heavier ball of the same size, which the air slows less.

Model builder: what a good response sounds like

Topic	A chain of cause and effect at standard	The shape it predicts
Body Systems and Negative Feedback	Skipping raises the heart rate; once it stops, the muscles need less oxygen, the change is detected and the heart slows again.	The heart rate falls quickly at first, then levels off at the resting rate; a longer skip gives a longer recovery.
Reproduction in Animals and Plants	Leaves make sugars by photosynthesis; the sugars feed the new root cells; but every leaf also loses water.	Roots rise with the number of leaves at first, then level off or fall as water loss starts to win.
The Carbon Cycle	Nearer the lamp the leaf gets more light, so it photosynthesises faster and takes in more carbon dioxide than respiration gives out.	The nearer the lamp, the further the indicator changes colour, until something else limits the rate and the change levels off.
Wave and Particle Models of Energy	A tighter slinky pulls back harder on each coil, so each coil moves sooner and the disturbance passes along faster.	The further the slinky is stretched, the less time the pulse takes to cross it.
Conservation of Energy and Efficiency	The ball keeps a share of its energy at each bounce; the rest becomes heat and sound.	The bounce height is the same fraction of the drop height every time: a straight line through zero.
The Atom and Radioactive Decay	Each die, like each nucleus, has the same chance on every throw, so the same share of those left goes each time.	The number left falls by about a sixth each throw, a curve that levels off towards zero; half are gone after about four throws, whatever the start.
Chemical Equations and Conservation of Mass	The atoms of the vinegar and the bicarbonate of soda rearrange into new substances, one of them carbon dioxide gas, which leaves the open cup.	The mass lost rises in step with the bicarbonate added, then levels off once the vinegar is used up.

A quick three-level guide

Move	Working towards	At standard	Beyond
Pose an investigable question	asks about one thing, or asks for an opinion	asks how one variable affects another, naming the controlled variables	chooses a question the class can test with the equipment it has
Build an explanatory model	repeats the pattern, or gives no reason	gives a chain of cause and effect from a named science model	says what result would count against the model
Test and refine	checks only that the result went up or down	checks the shape the model predicts and says whether the results support it	refines the model where the results drift, and plans a test of the refinement

A student at standard explains a pattern with a chain of cause and effect from a named model, and checks the shape it predicts. The skill grows all year, so keep the scaffolds coming back in every science topic.