ISBN: 9780262362979 | 381 pp. | March 2021

Variability and Consistency in Early Language Learning

The Wordbank Project

This book examines variability and consistency in children's language learning across different languages and cultures, drawing on Wordbank, an open database with data from more than 75,000 children and twenty-nine languages or dialects. This big data approach makes the book the most comprehensive cross-linguistic analysis to date of early language learning. Moreover, its data-driven picture of which aspects of language learning are consistent across languages suggests constraints on the nature of children's language learning mechanisms. The book provides both a theoretical framework for scholars of language learning, language, and human cognition, and a resource for future research.

Wordbank archives data from parents' reports about their children's language learning using instruments in the MacArthur-Bates Communicative Development Inventory (CDI); its goal is to make CDI data available for study and analysis. After an overview of practical and theoretical issues, each of the book's empirical chapters applies a particular analysis to the Wordbank dataset, considering such topics as vocabulary size, demographic variation, syntactic and semantic categories, and the relationship between vocabulary growth and grammar. The final three chapters draw on the preceding chapters to quantify variability and consistency, consider the bird's eye view of language acquisition afforded by the data, and reflect on methodology.


Table of Contents

  1. Preface
  2. 1. Theoretical Foundations
  3. 2. Practical Foundations
  4. 3. Methods and Data
  5. 4. Measurement Properties of the CDI
  6. 5. Vocabulary Size
  7. 6. Demographic Effects on Vocabulary Size
  8. 7. Gesture and Communication
  9. 8. Consistency in Early Vocabulary
  10. 9. Demographic Variation in Individual Words
  11. 10. Predictive Models of the Acquisition of Individual Words
  12. 11. Vocabulary Composition: Syntactic Categories
  13. 12. Vocabulary Composition: Semantic Categories
  14. 13. Morphology, Grammar, and the Lexicon
  15. 14. Morphological Overgeneralization
  16. 15. Individual Variation in Vocabulary
  17. 16. Variability and Consistency within and across Languages
  18. 17. Language Development at Scale
  19. 18. Beyond the CDI
  20. Appendix A: Individual Datasets
  21. Appendix B: Measures of Variability
  22. Appendix C: Stitching across Forms
  23. Appendix D: Estimating Age of Acquisition
  24. References
  25. Index