This book is a timely and important contribution to the study of language acquisition. It should be of value to those engaged in active research in this field, as well as to the general reader with an interest in language acquisition and linguistics. The papers are rather technical and may be difficult for the general reader, but the introductory essay by the editor, Brent, goes a long way to provide the background and describe the contents of the other essays in a more comprehensible language for the nontechnical reader. It should be pointed out, however, that this book is about language acquisition in general (including the theory of learning), particularly the computational approach in the research. It is not specifically concerned with second language acquisition.