Finding an exact coding schema to asses those elements of communication you are interested in will be difficult (although "Task analysis for groupware usability evaluation: Modeling shared-workspace tasks with the mechanics of collaboration", Pinelle et. al may be helpful). Instead, I would consider looking at various theories of communication (such as Media Richness Theory) and use those to guide a bottom-up analysis. Assessing the affective, verbal and behavioural aspects will be inherently interpretative so using someone else's coding scheme is unlikely to be very useful.

Hi Nadia,

You may find quite some usefull indicators here: Lahey L, Souvaine E, Kegan R, Goodman R, Felix S: A guide to the subject-object interview: Its administration and interpretation. Minds at Work, Cambridge, MA 2011 ISBN 978-1461128809

Best regards, Richard

Dear Nadia,

If I understand your question correctly, then I would say that the frequency count of exchanges for affective, verbal and behavioral interactions is the easiest way to approach your task (are these categories exclusive?) The simplest coding scheme, for verbal exchanges could be W, Ph, S whether they are at Word, Phrase or Sentence level for peer exchanges. I am a little confuse about the other two categories, but I believe they follow the same procedure WA, PhA, SA for words, phrases, or sentences expressing affection, and so on.

My five cents

Your research sounds very exciting, especially for its potential to shed light on peer-to-peer learning at the micro level. It's hard for me to really answer your question because it's very board in terms of the types of coding schemes you could employ. In other words, I don't know the theoretical and methodological lenses through which are viewing your research. If you were interested in philosophical thinking in upper elementary grades, I would check out some of the work that has come out of the International Assocation for Philosophy for Children, currently housed at Montlcair State University. Are you more interested in the linguistics? (Critical) discourse analysis? Learning sciences? 

Tell us us more and we can pool our knowledge.

be helpful for you to think more explicitly about what it is that you want to know about affective, social, and behavioral communicative actions. I can think of a number of coding schemes that focuses on the teacher and her/his communicative actions with students (Shirley Brice Heath's "Way with Words" (1980) leaps to my mind as a text that illustrates how we can make sense of learning in the classroom--in all its complexity--by examining communication. Kourtney Kazden's work might also be worth a quick look to help you think about what you mean by communication (verbal, tone, body language, other cues) with an eye towards thinking about affective, social, and behavioral 

As someone interested in how learning is expressed, I would also suggest thinking along pedagogical dimensions as well. The fact that you are interested in understanding what happens during peer-to-peer learning leads itself to a very interesting exploration into how peers engage in teaching and learning from each other. Pedagogical communicative actions can be affective, social, and behavioral. Not all affective, social, and behavioral communicative actions are pedagogical.