Phonological versus Lexical factors in Children's Productions at the Onset of Word Use Barbara L. Davis, Suzanne V.H. van der Feest and Hoyoung Yi * 1. Introduction At the earliest onset of word use, the growing number of recognizable and consistent attachments of vocalizations to particular word targets requires increasing precision in interactions of the systems supporting speech and language development (e.g. Davis & Bedore, 2013; Meltzoff, Kuhl, Movellan & Sejnowski, 2009). A major issue in fully understanding children’s formative stages of word- based speech and language acquisition relates to potential interactions between their available phonological and/or articulatory capacities (how they produce sound patterns) and their early lexical choices (what words they want to say) (e.g Stoel-Gammon, 2011). To consider the factors motivating observable speech output patterns, the question arises of whether children at the onset of word use mainly attempt to produce words consisting of sounds they can already produce, or whether young children pick word targets without much regard for the sounds in those words. Another relevant factor that we will consider here is vocabulary growth (i.e., how large is the child’s vocabulary overall?) Several studies have looked at the potential role of lexical versus phonological factors experimentally (e.g., Edwards, Munson & Beckman, 2011). However, few studies to date have concurrently analyzed phonological and lexical factors in children younger than four. Throughout this study, phonological production patterns will refer to children’s ability to execute speech movements, without making implications about the potential underlying phonological system involved in early speech production. Diverse theoretical perspectives consider potential interactions between phonological and lexical factors in the early stages of language acquisition. For example, a continuity assumption springing from a lexical dominance hypothesis * Barbara L. Davis (corresponding author), The University of Texas at Austin, Communication Sciences and Disorders, 2504 Whitis Avenue A1100, Austin, TX 78712, babs@mail.utexas.edu; Suzanne V.H. van der Feest, The University of Texas at Austin, Linguistics, suzanne@mail.utexas.edu; Hoyoung Yi, The University of Texas at Austin, Communication Sciences and Disorders, hoyoung@utexas.edu. This work was supported in part by NICHD R-01 HD27733-03 to the first author. We appreciate the statistical support of Sally Amen and Erika Hale of UT Austin’s Statistics and Data Science Department. Special thanks to Yvan Rose and the PhonBank team at St. John’s University, Newfoundland, for implementation of Phon analyses and ongoing Phon support. Lastly, our deep appreciation to all participating children and their families.