In situated studies drawing on cultural-historical activity theory, he has explored connections among writing, reading, talk, learning, and disciplinarity. This work has appeared in articles, chapters, and Writing/disciplinarity: A sociohistoric account of literate activity in the academy (1998). He has also co-edited with Charles Bazerman What writing does and how it does it: An introduction to analyzing texts and textual practices (2004). For further details see his homepage.