Correlation, causation, motivation, and second language acquisition.

Examines 4 truisms about correlation, demonstrating that they are not always true. For example, under certain conditions, correlation can imply causation, though these conditions are seldom satisfied in most applications. Nonetheless, many people are interested in investigating individual differences, and in making inferences of the type that this individual difference variable is related to, mediates, moderates, or even causes or influences that individual difference variable. Generally speaking, the analytic procedures used involve the correlation coefficient in one form or another. The author proposes 4 steps that researchers can follow to accumulate evidence that increases one's confidence in the validity of a particular causal model. These steps are illustrated by reviewing research on individual differences in 2nd language acquisition. This approach is not conclusive, but it does force the examination of the implications of the model, thus leading to further insights and research. Although the focus here is on 2nd language acquisition, the generalizations apply to other areas of research that are concerned with individual differences. (PsycINFO Database Record (c) 2010 APA, all rights reserved)