Odell, Lee and Dixie Goswami. “Writing in a Non-academic Setting.” Research in the Teaching of English. 16.3 (1982): 201-223

The authors work inside of generic bounds to get at the choices people make during drafting.  They go through people’s writing and look for instances of people using “dear_______”(generic elements of language)… here you say dear ____, in other places you say _______; would you change it to these other things, why or why not? This is one of the most sophisticated methods in writing research.