Fitze and approaches to evaluating CMC

I ploughed through Fitze's article today (Discourse and Participation in ESL Face-to-Face and Written Electronic Conferences). The thing that I was wondering about was the authenticity of the experiment set-up. It was extremely well-controlled, with Class A recorded talking about a subject F2F for a certain amount of time and Class B doing exactly the same in a chat, all at the same time, sitting at individual computers in a language lab. But does the Class B set-up reflect how chat is usually used? And do the results of the research therefore really reflect "real life" language teaching? How do the rest of you integrate chat into your syllabuses? Do you schedule lessons in the regular day-time timetable of the institutions you work for as an alternative to F2F session, or is it used as an additional/complementary means of communication - an extension of another class?