Pick up any journal and take a look at one of the articles. Without reading the main text, examine one of the figures and ask yourself, “What can I conclude from this image?” Are you able to answer this question? Based on the figure, can you guess what the article’s conclusions might be? Hopefully, yes!
Most people will agree that illustrations can greatly enhance reading comprehension. However, the problem we often face is how to create effective figures that best depict our data and conclusions. What’s more, we often struggle with explaining the significance of these images to our readers.
Figures and tables should not be only seen as supporting information; they should be able to stand alone. A reader should be able to look at the image, read its title and legend and grasp the takeaway message without having to rely on the main text. Indeed, people often look at the graphical elements in an article before they decide whether to read the rest of the article. Therefore, it is important to make your legends tell a clear story on their own.
In this post, we offer some key tips and reminders about how to write effective figure legends for journal submissions. For ease of reference, we’ve sorted the information into five categories: overall legend structure; title; materials and methods; results; and definitions. As you design the visual images to accompany your research, you should consider each of these elements.
17 Tips for Writing Effective Figure Titles and Legends
Keep the average length around 100-300 words.
Use complete sentences to aid comprehension, but phrases are permissible.
Use the same abbreviations, terminology, and units as in the body of your article, particularly in Methods and Results.
Always double-check your journal’s Guide for Authors for specific instructions about figures and captions.
For each figure, make sure the title can adequately describe all of the panels of that figure. If it’s not possible to create a single title that fits all, reconsider how you group the images.
Use descriptive language to highlight the methods or type of analysis performed (e.g., “Structural comparison of peptide-activated XY receptors”).
Use declarative language to emphasize a conclusion or major finding (e.g., “Compound ABC accelerates insulin production”).
Use the active voice with strong verbs.
Materials and Methods
Keep it brief. Only include information that is necessary to interpret the figure. The description might include details like the treatments and conditions applied or the models used. It should contain enough detail so the reader does not have to search the methods section for additional information.
Confirm whether the journal wants you to include or exclude from legends, the details regarding the methods and materials used.
Use past tense for verbs when discussing completed experiments.
Summarize the conclusion in one sentence.
If you use a declarative title, consider whether you should restate the results in the body of the legend.
Include sample size, p-values and number of replicates, if applicable.
Use past tense for verbs.
In the figure (not the legend), define any symbols, abbreviations, colors, lines, scales, error bars, etc. Also, label any other aspect of your figure that might not be readily understood.
Avoid naming conventions that are only used by your organization. Instead, use intuitive or standard names that outsiders can understand.
If you keep the above tips in mind as you draft legends for your figures and consult your target journal’s specific guidelines, you’ll be well on your way to improving your quality of writing and may also increase your chances of acceptance!
For additional information about how to write a strong research paper, make sure to check out our full research writing series!