Interactive Written Discourse as an Emergent Register
Ferrara, K., Brunner, H., & Whittemore, G. (1991). Interactive written discourse as an emergent register. Written Communication 8(1). 8-34.
This study examined 23 experienced users as they made travel plans with a central agent. Coding of the rates of usage for subject pronouns, copulas, and articles (and the omission thereof) showed that CMC was beginning to demonstrate characteristics of oral discourse. The authors claim that this sort of discourse exhibited enough consistent norms to be considered an emergent register, and that these norms may grow to influence or replace more traditional written styles. (And indeed, these things have become of great concern in some factions of writing instruction.)