The purpose of the study was to explore the extent of first-grade children’s academic vocabulary usage in writing. We additionally investigated the extent to which children who used more academic words tended to write compositions that reflected more phonologically and orthographically unique words and/or words with greater semantic challenge. The sample consisted of 191 first-grade control group children involved in a prior study. In the spring of first grade, after hearing a passage about a science topic, students were prompted to write an argumentative composition. Academic words were counted in compositions. Four predictor variables represented characteristics of words in the compositions—(a) phonological uniqueness (how similar a word sounds in comparison to other words); (b) orthographic uniqueness (how similar a word’s spelling is compared to other words); (c) semantic challenge (the age at which a word is commonly known) and (d) semantic concreteness (how tangible or imageable a word’s meaning is). The main conclusions were: Slightly more than half of the children included one or two academic words in their compositions, and greater inclusion of academic words in a composition was weakly associated with composition words that were more phonologically unique and more semantically challenging.
