When drafting your manuscript, there may be information that needed to be in a figure or table. The first thing that you should do is to decide which suits your purpose better. Tables are suitable for data having lots of variables or categories or the values that have the same pattern. Figures are proper for showing comparisons between groups in columns or associations in regression plots. Choosing one over the other can depend on space and the amount of data that you intend to present. Figures allow for the visual presentation of data, whereas tables allow space for more detail.
Do not repeat information in your text and tables or figures. It is not a good idea to give a list of numbers in the text while bringing the same list in the subsequent table. Likewise, you don’t need to visualize the information that is presented in a table through a figure and vice versa. If your table or figure are simple containing two or three columns and rows, it is better to summarize your information in a few sentences rather than using table or figure.
After presenting your data in a table or figure, you have to provide the reader with the context of the data. The guide which gives short textual information to the reader in interpreting what they see is called “legend”.
Figure legends are typically longer than table legends. The first sentence usually gives an overview of what is in the figure. For example,
“Figure 1. Flowchart of patient selection.”
After the title, you should give the reader enough background to understand what they see in the figure. An example of a complete legend is like this:
“Figure 1. Flowchart of patient selection. Inclusion criteria were age over 18 and no history of asthma. Patients were excluded if they had asthma, were using an inhaler, or were taking oral steroids.”
In cases that a figure has multiple parts or panels, it is better to label each with a letter: A, B, C, etc. in lowercase or upper-head letters depending on the journal’s guidelines. You can examine the last published papers of your target journal to know about this matter.
If you have panel labels, you should incorporate the letters and panels into a single file. You should not add them into a Word or other document files as extra images or text boxes on top of your existing figure image. In the legend, you should explain each panel that you label and give the reader a hint of what it shows. For example, with a fictional figure with two panels, A and B:
“Figure 2. The effects of risolol before and after animals were fed. (A) Risolol effects before feeding. Animals showed no changes in heart rate. (B) Risolol effects after feeding. Heart rate went up 10-fold, on average.”
A different way of providing that information would be like this:
“Figure 2. The effects of risolol before (A) and after (B) animals were fed. Animals showed no changes in heart rate before feeding, but the rate increased 10-fold on average after feeding.”
What matters most is telling the reader what the figure shows, on the whole. (“Effects of risolol on heart rate” or a statement, “Risolol affects heart rate after feeding”). In order to avoid cluttering up the image, we suggest the placement of the information such as P value in the figure legend in the figure itself.
Table legends, otherwise called “titles” differ from figure legends. They usually contain only a single phrase or sentences. For instance:
“Table 1. Patient characteristics.”
If you intend to provide more detail about the content of the table, you should place them in the footnote of the table placed after the table. In the footnote, define terms that you abbreviate in the table, indicate the meaning of any superscript symbols you use, and any other notes that help the reader understand what the table shows. These notes can contain information about comparison with different numbers of participants or a methodological difference between comparisons in the table.
The difference between table and legend
Normally a figure legend contains more detail and is placed above or below the figure as a single paragraph. Journals usually ask authors to put all figure legends in a single page following the reference list and upload the files of images separately.
Table legends, are usually short and located at the end of manuscript following the figure legend page, with one table in a page.
Some journals let authors to place figure, tables and legends close to where they are mentioned in the text. By consulting journal guidelines entitles as “Instruction for authors”, “Author information”, “Journal guidelines”, or “Submission information” you will know the requirements of your target journal.
Do not remember to cite in the text all figures and tables that you use in your paper. You also should number the figures and tables in the order that they appear in the text.
Citing figures and tables in the text
Journals are different in the way they ask these citations to look. In some journals the figure appears as abbreviated (e.g., Fig. 1), but in others they do not (e.g., Figure 1). The same applies to the use of panel labels in an in-text citation (e.g., Fig. 1A, Figure 1A, Fig. 1(a), etc.). looking at a newly published paper in your target journal is a good way of finding this out.
The abbreviated form of the word “table” is never used in the in-text citation. Journals usually ask authors not to produce tables that have different parts (e.g., a, b, c). If you have a table that you’ve broken into, e.g., Table 1a and Table 1b, you should either merge it into a single table 1 or break it into two tables, e.g., Table1 and Table2.
Journals have different approaches regrading supplementary material having tables and figure. Examples include Figure S1, Supplementary figure 1, Supplementary Fig. 1, Table S1, or Supplementary table 1. Elements occurring only in the supplementary material must be cited in the main text and numbered in the order that they appeared in the text.