Choosing a display means matching the type of data to the graph that shows its pattern honestly. The skill appears in data response questions and in fieldwork-style questions where you present or comment on results. It sits inside graphs, photographs and spatial data.
How do you match data to a display?
Ask two questions. What kind of data is it, and what do you want the reader to see?
| Data type | Message | Suitable display |
|---|---|---|
| Values over continuous time or distance | Trend or change | Line graph |
| Separate categories | Compare sizes | Bar chart |
| Parts of a whole | Share or proportion | Pie chart or divided bar |
| Two measured variables | Relationship | Scatter graph |
| Counts in continuous classes | Distribution | Histogram |
| Direction and frequency | Pattern by compass point | Wind rose or radial graph |
| Age and sex groups | Population structure | Population pyramid |
Worked example
All figures here are invented. A student records the main land use around a small town: housing 45%, farmland 30%, forest 15% and industry 10%. She wants to show how the land is shared.
Step 1, check the whole. 45 + 30 + 15 + 10 = 100, so the parts make a whole. A pie chart is suitable.
Step 2, convert to angles. A full circle is 360°, so each percentage is multiplied by 3.6.
- Housing: 45 × 3.6 = 162°
- Farmland: 30 × 3.6 = 108°
- Forest: 15 × 3.6 = 54°
- Industry: 10 × 3.6 = 36°
Step 3, check the angles. 162 + 108 + 54 + 36 = 360°. The chart can be drawn.
Step 4, label. Give the chart a title, label each sector and show the percentage on it.
What mistake do students make?
A student has monthly visitor numbers for three different towns and joins the towns with a line, as if the line showed a change from one town to the next.
Mistaken choice: line graph with Town A, Town B and Town C on the horizontal axis.
The line suggests there are values between the towns, and there are none.
The towns are categories, so a bar chart is correct. If the same student plotted one town’s visitors across twelve months, a line graph would then suit the data, because time is continuous and ordered.
Check yourself
All data is invented.
1. A class measures wind direction every day for a month and wants to show how often each compass direction occurs. Which display suits the data?
Show answer
A wind rose (or radial graph). The data is direction plus frequency, so showing it around a compass shape makes the pattern direct.
2. Land use is 52% crops, 28% grazing and 20% woodland. Calculate the pie chart angles.
Show answer
52 × 3.6 = 187.2°, 28 × 3.6 = 100.8°, 20 × 3.6 = 72°. Check: 187.2 + 100.8 + 72 = 360°.
3. A student plots house price against distance from a city centre for 30 houses. Which display, and what is it showing?
Show answer
A scatter graph, because there are two measured variables. It shows whether and how the two vary together, which leads into spotting unsupported correlations.
Where this leads next
Next, practise reading evidence that is not a graph in interpreting an annotated photograph. The statistics and distribution explorer lets you see how the same dataset looks in different forms. If graph choice is where you lose marks, a teacher in online one-to-one Geography tuition can check your choices on unfamiliar data.