Just about everybody will read through their text to proofread it before they send a document to their boss or to someone outside the company. However, many times they will overlook the figure title, axis labels, and legend text in their figures. These are locations that are impervious to spell checker diagnosis. Yet, the figures are probably looked at more closely by technical readers than the text itself. Engineers and scientists, in particular, like to pore over the plots to come up with their own interpretation of the data therein. That is why there is a greater likelihood that they will notice a spelling error embedded in a chart or graph more often than they will note typos in the text.
Just today I was editing a report and found an error in the legends of two consecutive figures:
1) “Pacjstone” should have been Packstone, and
2) “Sequebce” should have been Sequence.
I could not fix them, because they were pictures imported from some other program, probably Excel, and pasted as a photograph, not an editable MS Office Drawing Object.
Unfortunately, that means that nobody will be able to fix these errors down the line, so the full responsibility lies on the original author. Please take that responsibility seriously and proof your figures thoroughly before pasting them as pictures into your document.