The theme of this volume, complexity, accuracy and fluency (CAF) as dimensions of second language production, proficiency and development, represents a thriving area of research that addresses two general questions that are at the heart of many studies in second language acquisition and applied linguistics: What makes a second language (L2)…

In this article, I describe studies conducted over 25 years with secondary and post-secondary L2 learners in the United States. The evidence from these studies shows that there are important connections between students' early L1 skills and their L2 aptitude and L2 proficiency and that individual differences in students' L1 skills in elementary…

Suggests the use of principal components analysis as an alternative solution to the problem of grouping speakers by sociological characteristics prior to quantitative analysis. An example is presented of its application to vowel variation data collected as part of a sociolinguistic survey of English in Sydney, Australia. (Author/CB)