Understanding, Measuring, and Fostering Preschool Children’s Acquisition of Vocabulary Depth

Abstract

Much of the research on vocabulary development in preschool children has focused on the dimension of breadth, or the number of words known. However, vocabulary depth, or the quality of knowledge for known words, predicts reading comprehension above and beyond the contribution made by breadth. A focus on depth can also better inform instruction by providing more detailed information about children’s word-learning. This three-paper dissertation is aimed at clarifying depth as a concept, tracking how it develops and how it can be fostered in preschoolers, and examining how it can be measured. The first paper looks at preschoolers’ depth of learning for words from different form classes, examining the kinds of semantic information that were learned during a book-reading and play intervention. The second paper is a conceptual review of vocabulary measures used with preK-1st grade children. This paper maps these measures on to features of depth, making visible the aspects of word knowledge assessed by each, and also argues for the use and development of measures that tap higher-quality word knowledge. The third paper reports the results of an informational book-reading and play intervention designed to support preschoolers’ depth of word knowledge. This paper examines the impact of the intervention, and also looks at specific features of instruction and interaction that may contribute to depth, such as teaching words in taxonomies and the potential benefit of using target words in responsive interactions. As a set, these papers seek to add to the field’s theoretical understanding of depth and to shift the focus in vocabulary interventions and measurement to include a greater attention to quality of word knowledge.