Table of Contents
Summarize the Chart Data in Plain EnglishYou should try to encapsulate the entire story the chart is telling you. The caption occupies the top-most place in a chart, and the user can know what to look for in the chart. 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.
Include the Units of RepresentationYou should include the unit of representation of data in the caption, or in the sub-caption. For example, if your chart is about the half-yearly revenue of a company, you should use the caption “Half yearly revenue (2011)” with a sub-caption: “($ in millions)”. Usually, the unit is mentioned in a smaller font along the axes. Mentioning it in the caption gives the unit more visual prominence.
Include the Time PeriodIf your chart shows the trend of a data set over a certain period of time, make sure to mention it in the caption. It can be written as the sub-caption of the chart to save space, or if your caption is already long. Time period is generally represented in brackets.
Avoid Using Articles like “a”, “an”, “the”Another important rule is to keep the caption short and precise. Support the rule by avoiding the usage of unnecessary articles (a, an, the). Consider the two following sentences:
The annual revenue of the years 2010 vs 2011vs
Annual revenue of 2010 vs 2011The second option holds the specificity of the data without any loss of information. The unwanted articles have been removed without compromising the credibility of the chart caption.
Adjectives Are a Strict No-NoGet rid of adjectives. Stick to the previous rule. Consider the following two options:
Amazing Monthly Revenues for Model Tvs
Monthly Revenues for Model TSave the user from hyperbole. Again you can see that even when you exclude the adjectives, there is no loss in the integrity of the information. Instead, you present a more concise caption.