Computer-Supported Collaborative Learning (CSCL) technologies play an increasing role simultaneously with the appearance of the Social Web. The polyphonic analysis method based on Bakhtin’s dialogical model reflects the multi-voiced nature of a CSCL conversation and the related learning processes. We propose the extension of the model and the previous applications of the polyphonic method to both collaborative CSCL chats and individual metacognitive essays performed by the same learners. The model allows a tight correlation between collaboration and textual complexity, all integrated in an implemented system, which uses Natural Language Processing techniques.