That which is public in second language classrooms includes everything that we can perceive, including our students' use of language, our (the teacher's) use of language, and to a more limited extent our students' knowledge of language. Although patterns of communication in the second language classroom may also be largely visible (public), the discourse of the classroom is complex, multifaceted, and problematic and therefore requires more than simple observation to comprehend with any depth. That which is hidden (i.e., not obvious or visible based on mere observation alone) includes but is not limited to our students' frames of reference, our (teachers') frames of reference, the way we as teachers and the way our students perceive classroom discourse and interaction, and of course the cultural baggage that both teachers and students bring to the classroom.
This understanding characterizes classroom communication as multilayered (visible or "public" vs. not visible or "hidden"), multifaceted (the socially-constructed product of individuals' perceptions, backgrounds, frames of reference, language and real-world knowledge, personalities, cultural identities, and so much more), complex (requiring more than mere observation to understand) and problematic (unable to be adequately characterized by a simplistic framework and requiring theory and rigorous investigation to untangle). These realizations have important implications for language instructors. First, they inform us that the dynamics of communication in second language classrooms are often (perhaps always) more complex than they may appear--no matter what we see (or think we see) on the surface, there is far more beneath, driving what is above, that remains impenetrable to the naked eye (or ear). Moreover, our assumptions about communication and interaction in the classroom, largely determined by our individual and culturally-constructed "frames of reference," strongly influence our own communicative strategies, decisions, and patterns, even though we may be barely aware of them. We would therefore do well to investigate and better understand those assumptions.