We had problems with OCR. In some fonts, like Calibri and Arial, there are characters that look the same.
One potential source of confusion in Calibri is a visible homoglyph, a pair of easily confused characters: the lowercase letter L and the uppercase letter i (l and I) of the Latin script are effectively indistinguishable; this is true of many other common fonts, however.
Based on this article, I found that Consolas and Inconsolata give very good OCR results.
Both are available in Google Docs.