Traditional research into individual differences (ID) in second language (L2) learning is based on group studies with the implicit assumption that findings can be generalized to the individual. In this article, we challenge this view. We argue that L2 learners do not form ergodic ensembles and that language learning data lack stability. The data…

This study focused on the mechanisms underlying incidental second language (L2) vocabulary acquisition prior to formal instruction. We designed a cross-sectional study to examine which learner-related and word-related variables affect young learners' vocabulary knowledge at the level of meaning recognition and meaning recall. We collected data…