ACARA v9 CONTENT DESCRIPTION “construct and use representations, including tables, simple column graphs and visual or physical models, to organise data and information, show simple relationships and identify patterns”
Builds on putting counts into a tidy table and reading a column graph. Here the same set of measurements is organised three different ways: a table, a simple column graph and a visual model. The point is that one good representation makes a relationship and a pattern easy to read, while a careless one can hide them.
One soaking test, three ways to show it
You dip a sponge, a paper towel, a cotton cloth and a plastic sheet each into the same tray of water, then squeeze each one into a measuring cup to see how much water it soaked up in millilitres. That gives you four numbers. By themselves the numbers are easy to lose, so your first job is to organise them. A table does that: each material sits next to the amount of water it held. From that one tidy table you can then build other representations that make the pattern even easier to see.
Put the soaking amounts in a table, then draw the graph
Here is how much water each material soaked up. Look at the table, then switch to the column graph to see the same millilitres as bars.
Same data, two pictures. The table keeps every material beside its own number of millilitres. The column graph turns each amount into a bar, and the bars climb from plastic to sponge, so the pattern of which materials soak up more water is easy to read at a glance.
Reading the relationship in the bars
A column graph is more than a tidy picture. The height of each bar is the millilitres that material soaked up, so the tallest bar belongs to the material that held the most water. When the bars are lined up you can read a relationship: the amount soaked up depends on the material, climbing from the plastic sheet that soaks up almost nothing to the sponge that soaks up the most. Naming that simple relationship is exactly what the graph is for.
Build a visual model of the soaking, one material at a time
A visual or physical model shows the same data in a form you can see and touch. Add each material in turn and watch the picture of the pattern build up.
New evidence (1 of 4)
Glue a dry plastic swatch on the card and label it 2 mL. It barely changes, a tiny mark for a tiny amount.
Accepted model: Plastic soaks up almost no water, the smallest amount on the card.
Add the next piece of evidence and watch whether the accepted model holds or has to change.
Find the reading that breaks the pattern
When a representation is built well, a value that does not fit stands out. Suppose you test a new set of cloths from least to most absorbent and one reading drops far below the steady climb. On the graph that point sits well below its neighbours. A reading that breaks the pattern is not proof the test failed; it is a signal to measure that material again before you trust the whole picture.
Find the soaking amount that does not fit
Six cloths were ordered from least to most absorbent and the millilitres soaked up were measured. The amounts should climb steadily, but one reading does not fit. Click the one that breaks the pattern.
Click the point that does not fit the pattern of the others.
Which representations show the pattern?
Organising data well is a skill, and not every way of showing it does the job. A good representation keeps each material beside its own amount and makes the relationship easy to read. A careless one mixes the readings together or hides which material is which, so the pattern disappears. Telling a clear representation apart from one that hides the data is how you choose the right tool for the job.
Which choices organise the soaking data and show the pattern?
The aim is to show how much water each material soaked up and make the pattern easy to read. Decide which choices do that job and which hide it.
Claim: A good representation keeps each material beside its amount and makes the soaking pattern easy to read.
A table listing each material in one column and its millilitres soaked up in the next.
A column graph with a bar for each material, ordered from plastic up to sponge.
A visual model gluing a damp swatch of each material beside its amount.
Adding all four amounts into one total and showing only that single number.
A photo of the four wet materials piled together with no labels on it.
Decide whether each statement is evidence for the claim, or not.
Why it matters
Tables, column graphs and visual models are tools you will reach for again and again. A table organises what you measured, a graph lets a relationship and a pattern show themselves, and a model makes the same story something you can see and touch. Learning to build these representations, and to choose the one that shows the pattern honestly, is how a young scientist makes sense of what they have measured.
Quick self-check
1. You measured how much water each material soaked up. What keeps those measurements organised first?
2. Turning the table into a simple column graph helps because it...
3. On the graph the sponge has the tallest bar and the plastic sheet the shortest. This pattern shows...
4. A visual model that glues a wet-looking swatch beside each amount is useful because it...
5. One reading sits far below the others for a very absorbent material. That odd value...