From this model, it is clear that the success of reading for comprehension rests upon

(1) the possession and access of content knowledge relevant to what is being read;

(2) the possession and access of task-relevant information processing (procedural) knowledge, including planning or goal-setting (metacognitive) knowledge and knowledge of strategies for learning from texts; oral language representation knowledge (grammar:lexicon and syntax); communicative knowledge (such as questioning for clarification) and written language representation knowledge, including various communicative conventions developed by literates over time (such as topic sentence and supporting details in expository materials) and

(3) an external information display that can be accessed, scanned (read), and transformed into an internal representation in working memory for use in performing some task (reading-to-do) or with transfer to the long term memory or knowledge base when learning is desired (reading-to-learn).

Organizing these various components and processes of the human cognitive system into a program to help adults expand their knowledge of and skill in using graphics technology for reading is a formidable task. How one proceeds depends in large part upon the needs of the adults being served and the instructional contexts. For instance, adults with the absolute minimum knowledge of the alphabet, writing, and phonics require education in the alphabetic principle and its use in reading. There will be a need for extensive practice in decoding before these adults can give a skillful reading performance.

Engaging in Literacy Practices to Become Highly Literate. A salient finding from research across the last half century is that people with higher levels of education have higher levels of literacy skill and they engage in higher levels of literacy practices, i.e., they read books, magazines and newspapers more frequently than do the less educated and less skilled.

The combined evidence suggests that practice in reading, and especially the reading of books, is a potent contributor to the development of vast bodies of knowledge in long term memory and efficiency in word recognition and other aspects of the processing of language and graphic displays of information in working memory. In turn, it is the large bodies of knowledge that a reader possesses that permits him or her to provide a functional context for what they read. This makes it possible for highly literate readers to contend with even poorly designed and written books and other materials that are poorly contextualized. The highly literate reader uses prior knowledge to construct a meaningful context for the text, even when the text itself does not.

Some evidence exists to suggest that adult students who leave literacy programs may not only fail to develop additional literacy skills if they do not engage in further literacy practice, but also that they may actually, and fairly rapidly, lose new found skills if they are not practiced after the program 23 (p. 118). Literacy students who received job-related reading training and then went on to job technical training were re-tested about eight weeks after leaving the literacy program. It was found that at the end of the six week literacy program the students had gained 2.4 reading grade levels (RGL) of skill in job-related reading. Eight weeks later, after completing job technical training, that gain dropped to 1.9 RGL, for a retention rate of 80 percent. However, while gain in general literacy was about 1.0 RGL at the end of the job-related literacy program, eight weeks later that gain had dropped to 4 months, for a retention rate of only 40 percent of what had been gained in general literacy.