This book is based on research funded by the Economic and Social Research Council (ESRC) (reference number: C00428325005) and by a grant from Bristol University. I should also like to thank the following for their help and support during the preparation of this volume: Peter Robinson and Gordon Wells for advice during the planning and execution of the research; Sally Barnes, Mary Gutfreund, David Satterly, and Gordon Wells for giving me access to their data and documentation, and for answering innumerable queries about the fine details of their study; Dorothy Gibbs, Elena Lieven, Sara Meadows, Peter Robinson, and especially Lynette Dunn for their comments on earlier drafts; my parents, parents-in-law, and my wife Mair for their painstaking help with the tedious task of checking and correcting the manuscript; finally, the children themselves – Catherine Evans, David Gabica, Hannah Gillard, Helen Gordon, Siân Hewlett, Lawrence Humphries, Sophie Lane, Rachel Smith and David Trudgeon, who provided the material for Part II of the book, and, of course, their parents who suffered the inconvenience of a stranger entering their homes at regular intervals for a period of nine months.