Tips for Writing Great Chart Captions

      The old saying goes, “A picture is worth a thousand words.” However, without a caption, readers may get a thousand different messages from a picture and all of those messages may be wrong. In this article let us review a few tips in writing concise and telling captions.

1. Left Justify Captions Below The Figure

      Figures should be labeled with a number followed by a descriptive caption or title. Captions should be concise but comprehensive.They should describe the data shown, draw attention to important features contained within the figure, and may sometimes also include interpretations of the data. Figures are typically read from the bottom up, so captions go below the figure and are left-justified.

2. Summarize the chart data in plain English

      The caption occupies the top-most place in charts, and the user can know what to look for in the charts. For instance, in the chart below, the caption doesn’t tell the user what the comparison is about. The values don’t say whether they’re revenues, or profits, or losses.

JavaScript charts column chart

      Chart is from JavaScript chart library VanCharts

3. Simplify The Caption Information

      The most important consideration for charts is simplicity. Choose images the viewer can grasp and interpret clearly and quickly. Consider size, resolution, color, and prominence of important features. Charts should be large enough and of sufficient resolution for the viewer to make out details without straining their eyes. 

4. Keep The Caption Short And Precise

      An important rule of caption is to keep the caption short and precise. Consider the two following sentences:

      Market Share Percentage of January 2014 to January 2015

      Market Share Perc.(Jan 2014 to Jan 2015)

      The second option holds the specificity of the data without any loss of information.

      An important rule of caption is to keep the caption short and precise. Consider the two following sentences:

JavaScript charts column chart

      Chart is from JavaScript charts VanCharts

5. Limited Exposure Time

      Because you have worked on the raw data, created the chart, you are very close to your data. You know it inside out. But your audience is perhaps seeing this chart first time in their life. They are not going to see the raw data also. And they have under a minute to see, understand, analyze and agree/disagree to the point your are making. Given a limited time window, all that you can do to make their life easy is have all the elements of the chart in place. If you decide as a rule to use a title always in a chart, you can overcome the curse of knowledge and help your audience grasp your message easily.

      To sum up, there are five tips about the do’s of caption writing and another five tips about the dont’s of caption writing.

      The do’s of charts caption writing

      First three to five words grab attention and link chart and rest of caption

      Use a variety of adjectives and adverbs

      Use strong, visual, specific nouns

      use complete sentences

      The dont’s of charts caption writing

      Don’t editorialize

      Don’t use “during” as lead

      Don’t use “gag” or joke captions

      Don’t use “pictured above,” “shown above,” “seems to,” “attempts to”

      Don’t comment, question or talk to the picture