Data Authors: Skilled Designers of Data Presentations - Data Fluency: Empowering Your Organization with Effective Data Communication - page 118

4. Don't repeat yourself; repetition is bad. It's not necessary to have both a
legend and a title for single series graphs. Likewise, the title of a chart may
sufficiently explain what the reader is looking at, as shown in Figure 5-27.

BAD GOOD

Unit Sales by Month Unit Sales by Month

Sales

80 80

60 60

40 40

20 20

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Jan Feb Mar Apr May Jun Jul Aug Sep Oct

Figure 5-27: Remove repeated elements to clean up your charts.

A useful alternative to a legend is to label individual data series directly,
as shown in Figure 5-28.

WORSE BETTER

Unit Sales by Month and Product Unit Sales by Month and Product

80 80

Blueberries

60 60

Oranges

40 40

Blueberries

Oranges

20 20

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Jan Feb Mar Apr May Jun Jul Aug Sep Oct

Figure 5-28: Direct labeling of data series