This book combines a vast collection of data on phonological acquisition with close attention to Optimality Theory. It blends the studies of linguistics, psycholinguistics, and speech-language pathology in reference to phonological development. It also contains a step-by-step evaluation of competing theories while presenting a complete view of non-linear phonology, including adult grammar, psychological processing, first and second language acquisition, and inter-generational language changes. The authors focus on speech production rather than perception, emphasizing data from the period of real words. The many tables and phonological trees help to make this timely and useful study accessible to students and professionals alike. Among its key features it: addresses the full range of phonological patterns observed in children's speech; surveys patterns of development in children's speech; and provides the only existing single framework for children's phonological development.