Is there a better word to use instead of "area" for the conceptual use of the word? That is, I'm not referring to a physical space. Example: "Bob has a PhD in physics, so we trust his judgement in the area of mass balance." "Discipline" seems too specific. Any ideas?
Expertise, study, studies, field, matter. (Obviously, some of those don't work as a direct substitute in that specific sentence.)
Field works well. In addition to Packard's suggestions, you might go with "realm." Also, you might replace "the area of" with "matters concerning/relating to/regarding" or similar. You might also replace "in the area of" with "with respect to." In general, when considering replacing a word it pays to consider replacing some surrounding words as well.
"Field" becomes confusing in this context because I'm discussing oil and gas fields. Thanks for the other suggestions, I'm sure I'll get something figured out.
