A data-driven exploration of how children's language learning varies across different languages, providing both a theoretical framework and reference.

The Wordbank Project 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.

Michael C. Frank is David and Lucile Packard Professor of Human Biology and the Director of the Symbolic Systems Program at Stanford University. Virginia Marchman is Research Scientist at Stanford University. Daniel Yurovsky is Assistant Professor of Psychology at Carnegie Mellon University. Mika Braginsky is a PhD candidate in the Department of Brain and Cognitive Science at MIT.

Preface ix
Overview ix
Outline xi
How to Read This Book xiii
Acknowledgments xiv
1 Theoretical Foundations 1
2 Practical Foundations 15
3 Methods and Data 27
4 Measurement Properties of the CDI 45
5 Vocabulary Size 65
6 Demographic Effects on Vocabulary Size 85
7 Gesture and Communication 111
8 Consistency in Early Vocabulary 125
9 Demographic Variation in Individual Words 139
10 Predictive Models of the Acquisition of Individual Words 165
11 Vocabulary Composition: Syntactic Categories 181
12 Vocabulary Composition: Semantic Categories 203
13 Morphology, Grammar, and the Lexicon 221
14 Morphological Overgeneralization 243
15 Individual Variation in Vocabulary 255
16 Variability and Consistency within and across Languages 283
17 Language Development at Scale 289
18 Beyond the CDI 303
Appendix A Individual Datasets 311
Appendix B Measures of Variability 325
Appendix C Stitching across Forms 329
Appendix D Estimating Age of Acquisition 333
References 337
Index 357