School problems result from factors of three types: environmental, emotional, and developmental. The great bulk of illiteracy in this country derives from socioeconomic adversity and cultural alienation that presents a primarily political rather than a medical challenge. But some children, even when offered adequate schooling under tolerable conditions, fail to achieve at a level to be expected from normally intelligent children at that age. Such children often also appear to be emotionally disturbed, and it may be difficult to decide what is the primary cause of the school failure. There are some cases in which the emotional disorder was clearly antecedent. These I will not discuss. I will talk about children who underachieve for no obvious reason. Learning disorder is very much a matter of unexpected school failure, of the child doing less well than his parents or teachers expected. Before he does anything else, the clinician needs to satisfy himself that the child is really underachieving. There are two parts to this investigation: achievement tests and intelligence tests. It is not necessarily true that the child is doing badly because the teacher says so nor because the parents say so. You cannot know whether the child in fact is falling well short of national norms without a reading achievement test such as the California, Metropolitan, or Wide Range. An advantage of these tests is that they do not only give information about the child's ability in reading and writing, which for some reason are almost the only subjects ever complained of (and on which I will, therefore, concentrate), but they also measure his ability in arithmetic.