A sound knowledge of the psychological processes which underlie normal reading can be expected to facilitate an understanding of the causes of reading disability. This expectation is consistent with the fact that diagnosis and management of reading disabilities discussed in this book are explained within the framework of cognitive psychology and neuropsychology. Unfortunately, the information we have about the normal reading process is incomplete. There are several reasons for this. First, reading is an extremely complex mental operation. As Huey (1908) observed many years ago, to completely analyze what we do when we read would be almost the acme of all psychologists’ achievements. Second, psychologists very often study reading behavior as a means of understanding the fundamental cognitive processes and not because they are interested in reading per se. Finally, reading is not a unitary phenomenon; rather, there are several varieties of reading behavior and different kinds of readers: Careful reading is different from skimming and scanning; reading a novel is different from reading a textbook; and beginning readers are different from skilled readers. Depending upon the material being read and the purpose of reading, different subprocesses are likely to be brought into play.