An investigation of the stability and replicability of aptitude, attitude, and achievement factors in second language acquisition used 31 groups of over 100 second language students each from five grade levels (7-11) and seven Canadian geographic areas of varying degrees of bilinguality. The groups were administered a series of related measures that were factor analyzed within groups. Although the number and type of variables used in the groups varied slightly, these primary factors emerged: integrative motive, French achievement, self-perception of French competence, language aptitude, evaluation of the learning situation, evaluation of the French teacher, evaluation of the French course, multilingualism, and semantic differential. Another set of analyses involved the factor analysis of the original factor matrices for a more rigorous test of comparability across samples. This demonstrated that the factors of evaluation of the learning situation, self-perception of French competence, French achievement, and integrative motive were consistent across all grade levels within monolingual regions and across lower grade levels within bilingual regions. Similar consistency was demonstrated only for the factors of evaluation of the learning situation and integrative motive within bilingual regions for the upper level students. Interpretations for these results are offered. (Author/MSE)