part 1 deals with the theory of speech disorder and includes an epidemiological study of 320 children with disordered speech, as well as examining the relationship between different speech and language disorders.part 2 focuses on intervention issues, setting out a schema for decision-making and providing a procedure for the differential diagnosis of subgroups of speech disorder and evaluates the approach to classification and intervention in a large randomized control trial.part 3 deals with special populations, including children with intellectual impairment, hearing difficulties and those with auditory processing problems and the book ends with a chapter on bilingual children with speech disorder.in the ten years since the first edition was published, knowledge about the subject has greatly increased and this is reflected in the heavily revised contents.the book clarifies salient issues and provides critical summaries of current knowledge.