A study was conducted to examine children's use of social factors as bases for evaluating different patterns of code switching in dyadic social interaction. The factors were role-related and social norms, interpersonal accommodation, intergroup biases, and socio-cultural status. An initial study was conducted of monolingual and bilingual English Canadian and French Canadian senior high school students from Montreal, who were tested in classroom groups, one group per condition. Analysis of the data indicated that the basis for evaluating code switching changed both as a function of ongoing discourse and as a function of the sociocultural and role characteristics of the interactants. A second study was conducted with fifth grade French Canadian and English Canadian children. The French-speaking children had been in regular French schools, and the English-speaking children had been in early French immersion programs. A preliminary analysis of the available data indicates that generally the children's reactions appeared to be based on more concrete, immediate factors than was the case for adolescents. One prediction suggested by the available evidence is that comprehension of the social significance of language variation will precede actual use of code switching to signify attitudes, beliefs, or intentions. (AMH)