3 Tips for writing an effective figure caption
In a recent post on constructing effective tables and figures, I noted the need for figures to include captions that “succinctly describe the accompanying content.” In this post, we will discuss the purpose of captions and how to write one that is effective.
It is important to remember that figures should be clearly understood, even in isolation from the rest of the manuscript. The caption provides an opportunity for the author to provide context and connection to the rest of the article, as it relates to the visual element.
Focus your caption
Your caption should be limited to a description of the figure, not the larger research process. Clearly and succinctly describe the visual elements of the figure. As a general rule, limit the caption to between 100 and 300 words.
Be detailed in your description
If there are multiple panels or sections to the image, such as multiple series in a chart, or parts of a diagrammed process, describe each in your caption. If length becomes a concern, consider breaking the image into multiple figures for the independent components.
Tell a story
Begin with a title that identifies the overall purpose of the figure. Include any methods necessary for understanding or interpreting the basis for the image details, but be brief in the discussion of methodology. Close with a single sentence that summarizes the results or implications of the presented content.
Figure captions allow the image to be accurately interpreted independent of the manuscript. A clear understanding of why you have included the figure in your article is the foundation for telling the right story in the associated caption. Be consistent with the narrative and remember that the figure itself (and the caption by association) should supplement, not duplicate the article contents.