The study described here was intended to test Basil Bernstein's contention that different types of speech patterns can be identified for lower and middle class children, and that lower class children may, because of their speech behavior, have difficulty in performing cognitive tasks necessary for success in the school situation. Spontaneous speech samples were collected "unobstrusively" by an observer who recorded, verbatim, the verbal interactions between fifty lower and fifty middle class mother-child pairs in a doctor's waiting room. These interactions were analyzed according to formal categories, such as the number of words used, and to content categories based on the nature or purpose of the interchange. The authors found that the language used by the two different groups fell into divisions very similar to the language modes described by Bernstein, a lower overall verbal productiveness being typical of the lower class group. The authors feel that if the observations made in waiting rooms can be assumed to be valid for other contexts as well, then this study can be said to support the notion that the home situation gives middle class children an important advantage in school, as well as the idea that compensatory programs may be necessary for lower class children. (FWB)