Pictorial and Graphical Representation of Data
The common ways to show data: pictograms, bar charts, pie charts, line graphs and scatter charts, and how to pick the most suitable chart for a set of data.
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Showing data
Numbers on their own can be hard to understand, so statisticians turn them into pictures and graphs. Each kind of chart suits a different kind of data. This module looks at the common charts, what each one shows, and how to choose the most suitable one.
Words for charts
Learn these four chart types before you study how to choose one.
Bar chart or pie chart?
Two of the most common charts show data in different ways.
Choose the chart, say why
A top answer chooses the most suitable chart and says why. Use a pie chart for proportions of a whole, a bar chart to compare categories, a line graph for change over time, and a scatter chart for the link between two things. Remember a pictogram always needs a key.
Match the chart
- pictogram
- bar chart
- pie chart
- line graph
- uses symbols, where each symbol stands for a number
- bars with gaps, comparing separate categories
- slices of a circle, showing parts of a whole
- points joined by lines, showing change over time
Pick the chart, and the reason
- how sales change over each month
- the proportion of a class who like each sport
- the number of pets of each type
- the link between height and shoe size
- a line graph, because the figures form a sequence and the shape of the trend is the point
- a pie chart, because everybody counted falls into exactly one slice of a single group
- a bar chart, because the labels are separate with no order, so the bars need gaps
- a scatter chart, because every person supplies two measurements plotted as one point
What does a pie chart show?
What does a pie chart show best?
- How a whole is split into parts, or proportions.
- How data changes over time.
- The relationship between two variables.
- How spread out a set of values is.
Features of a pictogram
Select the TWO things a pictogram must have.
- A symbol that stands for a number.
- A key that explains the symbol.
- Slices of a circle.
- A line of best fit.
Order the steps
Put the steps of drawing a chart in order, earliest first.
- Collect the data
- Choose a suitable chart for the data
- Draw the axes or the key
- Plot the data and add a title
Summarise the charts
A _____ uses symbols with a key, where each symbol stands for a number. A _____ chart uses bars with gaps to compare separate categories. A _____ chart shows the parts of a whole as slices of a circle. A _____ graph shows how data changes over time. A _____ chart shows the relationship between two variables.
Read the pictogram
In a pictogram each symbol stands for 10 people. How many people do 4 symbols represent?
Find the category charts
Tap the TWO charts best for comparing separate categories.
- Bar chart
- Line graph
- Pictogram
- Scatter chart
- Pie chart
Which chart is best?
Choose the most suitable chart for each set of data.
- You want to show how the temperature changed each hour during a day
- You want to show what proportion of a budget is spent on each item
- You want to see if taller people tend to have larger feet
Choose a chart
A student has data on how many people walk, cycle, drive or take the bus to school. Explain which chart would be most suitable to show this data and why.
- Name the most suitable chart
- Explain why it suits this kind of data
- Explain what the chart would show the reader