Stoel-Gammon (this issue) states that "from birth to age 2 ; 6, the developing phonological system affects lexical acquisition to a greater degree than lexical factors affect phonological development" (this issue). This conclusion is based on a wealth of data; however, the available data are somewhat limited in scope, focusing on rather holistic measures of the phonological and lexical systems (e.g. production accuracy, number of words known). Stoel-Gammon suggests a number of important avenues to pursue, but does not discuss a critical one that is emerging in the broader literature on word learning. Specifically, recent connectionist models and adult word learning research provide evidence that greater differentiation of the cognitive processes that underlie word learning yields new insights (Leach & Samuel, 2007). This approach may be fruitful for future investigations of the relationship between phonological and lexical development in young children.