ACARA v9 CONTENT DESCRIPTION “create different graphical representations of data using software where appropriate; compare the different representations, identify and describe common and distinctive features in response to questions”
The descriptor asks for something subtle: not just making a graph, but making different representations of the same data and comparing them — using software where appropriate, which is exactly what this page is. So one little survey runs through the whole unit: twenty-one children, four ways of getting to school. It becomes a tally, a table, a picture graph and a column graph, and the real lesson lives in the gaps between those forms: what every honest picture must agree on, and what each one does better than the rest.
The tally and the table
Before any graph there is a count. Tallies are how a count stays honest.
Twenty-one kids answered. Run the survey and count them as they come.
From answers to a table
Every graph begins as a count, and the tally is the count's working diary: one stroke per answer, with the fifth stroke laid across its four friends so the bundles can be skip-counted in fives later. When the survey ends, the tally retires and the table keeps only the totals. Children should feel that hand-off — tallies are for during, numbers are for after — because choosing the right recording tool for the moment is the first data decision they will ever make, and it is already a real one.
The picture graph
Every child becomes one square. The data turns into something you can see.
One-to-one: counting squares is counting children, no scale required.
One square, one child
The picture graph is counting made visible: one square per child, rows that grow with the answers, no scale to interpret at all. At Year 2 the correspondence stays strictly one-to-one, and that is its superpower — a child can put a finger on each square and name the classmate it could be. It is also its limit, quietly planted here for Year 3: when a hundred children answer, nobody wants a hundred squares, and the idea of one symbol standing for several will arrive as a relief rather than a rule.
The column graph
The same survey again, but now a height carries each number.
Find the column, then slide straight across to the scale on the left.
Read the height, not the pieces
The column graph makes a genuine leap: the number is no longer a crowd of pieces but a single height, read against a scale. That is a new skill — find the top of the column, slide across, read the line it meets — and it deserves slow practice, because every graph the child meets from here to adulthood works this way. Notice what was traded: the columns are quicker to compare than rows of symbols, but the one-by-one countability is gone. Nothing in data display is free.
Side by side
The descriptor in one canvas: two representations of the same data, compared.
One survey, two costumes. Hunt for what they share and where they differ.
Same survey, two costumes
Putting both graphs on one canvas turns the descriptor's words into a game: common features are everything the data forces — the counts, the order, the winner — while distinctive features are everything the format chooses, like symbols versus heights. Children who can say both sentences out loud, what is the same and what is different, are doing real statistical thinking: separating the facts from the presentation. That habit, fully grown, is how an adult reads a chart in the news without being fooled by it.
The right graph for the job
Graphs are tools. The question decides which tool to reach for.
Match the job to the graph. Sometimes both will do; sometimes one is clearly better.
The right graph for the job
The closing judgement calls are the descriptor's final clause in action: features are compared in response to questions, because the question is what makes one representation better than another. Need an exact one-by-one count? Pictures. Need room for a hundred answers? Columns and their scale. Just need the winner? Either will shout it. With this unit done, the Year 2 Statistics strand is complete — data gathered, displayed two ways, and judged — and the surveys only get bigger from here.
Quick self-check
1. In the picture graph, each square stands for...
2. 8 children chose car and 3 chose bus. How many more chose car?
3. Both graphs show the same survey. The most popular way to school is...