Use titles to amplify the message
Typically, chart titles should state what the chart is showing. In some cases it’s useful to use the title to amplify the main finding in a compelling headline, for example: Student numbers have risen by 5% since 2010. This approach will aid the understanding and describe the takeaway message.
Label the axes
Always label the axes. If the labels you are using are long, it’s best to display them horizontally so they are easy to read. In this case choose a horizontal design for the chart. Showing the unit of measurement once can also help reduce the clutter on the axes.
When producing the axes, consider limiting a number of tick marks which should reduce the clutter in your design.
Proofread your work
It’s so obvious, after all we proofread and spell-check other type of written work and yet quite often we focus so much on the numbers that we forget about words, their spelling, grammar and clarity of the message.
Apply consistent formatting
Well formatted charts are much easier to read. Limiting the font type to two or three with consistent size will make the charts look more professional. According to advice provided by Tableau, for best performance you should choose from the following fonts:
- Trebuchet MS or Verdana (especially for tables and numbers)
- Times New
- RomanLucida sans
Be consistent with the font size and make sure that the font used is not too small. It’s best to limit the variance of font sizes, for example do not use 8-point type on an axis and 20-point type for the axis label.
In terms of making your charts clearly visible and accessible to people with visual impairment or dyslexia, the advice provided by Jisc TechDis is to use a 12 point san serif font in printed documents. However, that is just a general guide because different fonts can have different sizes in millimetres.
If you intend to show your charts in PowerPoint presentations, the recommended minimum font size would be 24. Charts embedded in Web pages can include text in any size as long as it is flexible and can be changed in the users browser.
Try to keep the same formatting style throughout all charts presented at the same time.