In this blog, I describe information provided in the AMA Manual of Style that covers how to deal with figures. This information is located in Section 1 “preparing an article for publication”, subsection 4: visual presentation of data, and sub-sub section 4.2, there you have the information about figures. Of course, for all the finer details about this topic, please do visit the AMA Manual of Style.
Ok, so here is what the AMA Manual of Style has to say about figures.
First of all, this section is broken out into several categories. These are
4.2.1 Statistical Graphs
4.2.5 Photographs and Clinical Imaging
4.2.6 Components of Figures
4.2.7 Titles, Legends, and Labels
4.2.8 Placement of Figures in the Text
4.2.9 Figures Reproduced or Adapted From Other Sources
4.2.10 Guidelines for Preparing and Submitting Figures
4.2.11 Consent for Identifiable Patients
The first few sections drill quite deeply into the various types of graphs, diagrams, maps and illustrations. It’s worth checking this out. In this discussion, I will focus in on the Components of Figures, which is section 4.2.6, and also the Title, Legends and Labels, section 4.2.7.
According to the AMA Manual of Style, “clear display of data or information is the most important aspect of any figure.”
They go to a little bit into scales for graphs, describing the range of values, axis scales and axis labels. An important point is that the range of values on the axes should be slightly greater than the range of values being plotted so that the entire data set can appear within the area defined. And, ideally the range should include zero on both axes if zero is a possible value for what’s being displayed. And then, if there’s a break needed in the axes because of the extent of the range of data, then you can signify a missing portion of the range with paired diagonal lines.
When talking about axis scales, simple multiples of the quantities plotted should be included and the values on the axis scale should be centered on their respective tick marks. Both linear and logarithmic scales can be used. For linear scales, the axis must appear linear, with equal intervals and spacing between tick marks.
Axes should be labeled with the type of data plotted and the unit of measure used.
Symbols, line styles, colors, and shading characteristics can be directly labeled or included in a key. This information can also be included in a figure legend.
The form of labeling or the key used should be consistent throughout figures in a single article. It’s also important to use two easily differentiated colors or shades for different data. Often an unfilled circle will depict placebo and a filled circle will depict study drug for example, which is clear and makes sense.
They also point out that shading is preferable to crosshatching and other types of patterns to differentiate different groups. And then often error bars are included and this should be drawn to encompass the entire range of variability not just one direction. The error bars should always be defined either in the legend or on the plot itself.
In most cases figures should not be presented in a 3-dimensional way.
Next is titles legends and labels which is section 4.2.7
The figure titles in most journals are published directly under the figure and will be numbered consecutively, unless only one figure is included in the article and then it will be called just “figure”. I always remember that tables begins with “T” and therefore their title goes on Top, above the table, whereas, figure does not begin with T and so the figure title goes beneath the figure. Just a little pneumonic to help remember…
Figure titles should be written as a clause or phrase identifying the specific topic of the figure and each major word (of 4 letters or more) of a title should be capitalized which would follow the same rules as for article titles.
Titles of figures should not begin with a phrase identifying the type of figure. So you would not say “a photograph showing x,y,z” you would just say “x,y,z”, although a description of the type figure may be required in certain circumstances, to avoid confusion and to add clarity, eg multislice CT-angiography.
Figure legends should be written below or next to the figure in sentence format. The legend contains information that describes the figure and it shouldn’t be longer than 40 words in general but longer legends may be used if more detailed explanation is required for a given figure. Figure legends should also contain expansions of abbreviations and footnotes for information that is too much to include in the figure itself.
When it comes to labels, axis labels should be capitalized, similar to a column heading in a table. Sentence style capitalization should be used for non-axis labels within the figure itself (easier to read)
Well that’s it for now. Thanks for joining me. If you need medical writing assistance, please check out email@example.com, and if you are interested in getting into medical writing, please visit 6weekcourse.com