Sociolinguistic data regarding code selection and nonverbal modes of learning are examined in the gesture communication system of the (Oglala and Brule) Sioux. Sign language is viewed as an extra-linguistic mode of communication currently in use in Indian classrooms. It is one alternative to literacy as a means of communication; however, this is not to suggest that sign language be adopted in place of literacy for formal education. Analysis of contextual uses of sign language suggests that some nonverbal learning may enhance classroom participation and, in some situations, have more cultural salience than literacy. Sign language represents an example of a code which may be selected from the communicative repertoire of the community. Since sign language usage depends on an internalization of the verbal categories, the internal structure and syntax is maintained despite the transferral to nonverbal grammar. Furthermore, its use is nonrandom; it is definitely patterned and subject to social constraints and sociolinguistic pressures. (Author/LG)