- In writing my thesis in geosciences I have a number of figures with a fair amount of text content. Is there some limit I should adhere to -- say for example max 5 lines -- before I should just write 'refer to text'?
- A related question is where citations should go, especially in the case of several needed for one figure (e.g. a plot of n sets of data from n different sources). Again, is there some point where I should say refer to text for citations?
I would imagine this may vary from field to field, but in the biological sciences the caption text in journal publications is often verbose to the point of absurdity. That being said, I would simply use common sense; If the description takes more than a paragraph, you should definitely "refer to text". Generally speaking, the caption is simply a textual guide as to how to read the plot, with (maybe) a sentence drawing the reader's attention to a particular feature of the plot. It should mostly describe the plot, and only sparingly discuss it.
An expert in the field should be able to understand most of the content of the figure from the figure and caption alone. The caption should be long enough to admit this, but no longer. If your captions seem to need to be pages long, then you need to work on making your figure adhere better to standards in the field or to be intuitively clearer.
If you run out of time to make it comprehensible, keep the caption comfortably smaller than the figure itself; having a tiny figure with a huge block of text just looks wrong. It takes a long time to make really clear figures, but you can at least get the superficial style right quickly enough.