Right data, wrong chart
Priya has good data on lunch sales. She draws a pie chart with eleven slices for the head teacher, who has one minute.
Nobody can read it. The data was fine. The technique did not fit. Here are the criteria that stop this.
Key words
| Word | What it means | Example |
|---|---|---|
| Criteria | The tests you use to choose between options. | Brief, audience and skill level |
| Brief | The written request that says what the message must do and any limits. | One slide for the head teacher |
| Technical knowledge | How much the reader knows about data and its words. | Knows what a median is |
| Role-specific | Chosen to suit what the reader does at work. | A buyer needs stock levels |
| Clutter | Too many items or marks on a chart, so the point is lost. | Eleven pie slices |
| Technique | The type of chart, table or picture you choose. | A bar chart |
| Dashboard | One screen of charts and figures that update as data changes. | Live stock levels |
| Heat map | A grid where shade shows how big each value is. | Busy times by day |
The cells students fill in are left blank in this preview.
By the end of this lesson
Note
I can choose a visual technique using the brief, the audience, their skill with data and their role.
Starter: what you already know
Have a go
Starter: what you already know
3 questionsYour answers are marked here and are not kept. A college account keeps every student’s marks.
Four things decide the choice
First, the brief: what must it do, and what are the limits? Second, the audience: who reads it? Third, their technical knowledge: do they know the data words? Fourth, the role: what do they do at work, so what do they need?
Put these four together and many techniques drop out.
Four briefs and a good choice
| Brief | Reader and role | Technical knowledge | A good choice |
|---|---|---|---|
| One slide on term sales | Head teacher, decides budget | Low | A bar chart with a clear title |
| Sales trend over three years | Finance lead | High | A line graph with axis labels |
| Is warm weather linked to salad sales | Data colleague | High | A scatter graph with the pattern noted |
| Show every meal price | Cook, looks up prices | Low | A table with large print |
The cells students fill in are left blank in this preview.
Check: which chart suits this brief?
Have a go
Check: which chart suits this brief?
4 questionsYour answers are marked here and are not kept. A college account keeps every student’s marks.