Sometimes you do not start from data. You want to know what a dumbbell chart is, whether a radar chart is ever a good idea, or what to suggest instead of the pie your client asked for. That is what the chart map is for.
Open the map
In Chart Compass, press Chart map, the first tab of the switch at the top of the left side. The screen turns into eleven lanes, one per goal, each with its charts drawn small. The map remembers it was open, so next time you start where you left off.
The lanes are the eleven goals from lesson 3, A to Z: Against a target, Change over time, Compare, Distribution, Exact values, Flow and process, One number, Part of a whole, Places, Ranking, Relationship. Each lane shows how many charts it holds.
Filter by what you want to say
On the left, under the switch, is a list of filters: Everything first, then one per goal, each with how many charts it shows. Press Part of a whole. The lanes and charts that do not fit fade, and the ones that do stay bright, including charts that live in another lane but can also show parts, such as the waterfall and the stacked area chart.
Many charts answer more than one goal. A bar chart compares and ranks. A column and line chart shows change over time and a target. The filter shows every chart that can do the job, not only the lane it sits in.
Find a chart by name
The search box sits in the app bar, so you can use it from Ask me too: press / and type. It knows each chart's name and its Power BI name, so bullet, matrix and scatter all find their chart, and so does decomposition. Typing opens the map if you were not on it.
Open a chart
Press any chart. A popup shows the chart drawn large, the goals it answers under its name, and:
- Use it when: the situation it is made for
- Skip it when: how it misleads
- How to read it: what the reader should look at first
- Tip: one thing that makes it better
- The data it needs: the columns it takes
- Build it in: its names in Power BI, Tableau and Excel
- Similar charts: others that do the same job, one press away
If you brought data in Ask me, the chart is drawn with your data, with the fields it would use. If your data does not have the right shape for it, a note says so and shows a sample instead.
Charts worth knowing
A few charts on the map solve problems that people usually solve badly:
| Chart | Use it instead of |
|---|---|
| Bullet chart | A row of gauges: one compact bar per item, with its target |
| Variance bars | Two bars per item: shows only the gap, coloured by sign |
| Dumbbell chart | Clustered bars for before and after: two dots joined by the change |
| Slope chart | A crowded line chart when only the first and last period matter |
| Lollipop chart | Heavy bars when many values sit close together |
| Strip plot | An average alone: every value as a dot, so the spread shows |
Use the map to say no
The most practical use of the map is a polite no. When someone asks for a pie with ten slices, open Pie chart and read Skip it when together: Many slices or close values: angles are hard to compare. Then open Bar chart and show the alternative, drawn with the same data.
That completes the course. You can now take any data, say what it should show, and build the chart that shows it, with a reason for every choice.