This is a book about children like Angela and Michael: intelligent children who have a significant and unexplained difficulty in learning. Each child with such difficulties is unique, but they have enough in common with one another for their condition to be summarized by one collective term. I shall use the term ‘specific learning difficulties’ as an umbrella term for this whole group of disorders. A specific learning difficulty can be defined as: . . . an unexpected and unexplained condition, occurring in a child of average or above average intelligence, characterized by a significant delay in one or more areas of learning. . . . In order to understand this definition fully, a number of important questions must be answered. Which areas of learning are involved? What is a ‘significant delay’? Which other causes of difficulty must be excluded? Let us look at these questions one by one. . . . Which areas of learning are involved? . . . The areas of learning involved in specific learning difficulties can be divided into two groups. The first group consists of the basic academic skills: reading, writing, spelling, arithmetic, and language (both comprehension and expression). These are relatively easy skills to measure, and are of central importance to success at school. The second group contains areas of learning that are also vitally important, but are far less well understood. These involve the learning of skills such as persistence, organization, impulse control, social competence, and the coordination of movements. I shall use the term specific learning difficulty to cover significant delay in any of these areas. Children may have only one area involved, or a number of areas. I am, therefore, using the term ‘learning’ in a broad sense, to include all areas of learning, not only academic areas. There are good reasons for grouping all these difficulties together. It has been well established that difficulties in these different areas of learning are closely related. They often coexist in the same child, they are all more common in boys, they all share the same theories of causation, and they all share the same general principles of management.