ABSTRACT
It is now well accepted that reading consists of two components, decoding and comprehension (Aaron, Joshi, & Williams, 1999; Gough & Tunmer, 1986; Hoover & Gough, 1990). Decoding is the word recognition process that transforms print to words, whereas comprehension assigns meaning to words, sentences, and texts. It is also now widely accepted that reading is a language-based skill (see Catts & Kamhi, 1999). Word recognition relies heavily on phonological and lexical knowledge, whereas comprehension of larger discourse units requires syntactic, morphologic, semantic, and discourse knowledge. Alogical consequence of the language bases of reading is that children who have deficiencies in one or more aspects of language will experience difficulty learning to read. Considerable evidence has accumulated over the last 25 years documenting the strong relationship between phonological knowledge and word recognition skills and the importance of semantic, structural, and discourse knowledge for reading comprehension. Nonlanguage factors, such as emergent literacy experiences, nature of instruction, naming speed, motivation, attention, perceptual, conceptual, and reasoning skills also affect reading ability. Al-
1Portions of this chapter were adapted from H. Catts & A. Kamhi (1999), Language and Reading Disabilities, Boston: Allyn & Bacon. Reprinted by permission.
