Bottom-up theories hypothesize that learning to read progresses from children learning the parts of language (letters) to understanding whole text (meaning). Much like solving a jigsaw puzzle, bottom-up models of the reading process say that the reading puzzle is solved by beginning with an examination of each piece of the puzzle and then putting pieces together to make a picture. Two bottom-up theories of the reading process remain popular even today: One Second of Reading by Gough (1972) and A Theory of Automatic Information Processing by LaBerge and Samuels (1974). Gough’s (1972) One Second of Reading model described reading as a sequential or serial mental process. Readers, according to Gough, begin by translating the parts of written language (letters) into speech sounds, then piece the sounds together to form individual words, then piece the words together to arrive at an understanding of the author’s written message. In their reading model, LaBerge and Samuels (1974) describe a concept called automatic information processing or automaticity. This popular model of the reading process hypothesizes that the human mind functions much like a computer and that visual input (letters and words) is sequentially entered into the mind of the reader. Almost without exception, humans have the ability to perform more than one task at a time (computer specialists sometimes call this “multitasking”). Because each computer (and by comparison the human mind) has a limited capacity available for multitasking, attention must be shifted from one job to another. If one job requires a large portion of the available computer’s attention capacity, then capacity for another job is limited. The term “automaticity” implies that readers, like computers, have a limited ability to shift attention between the processes of decoding (sounding out words) and comprehending (thinking about the meaning of the author’s message in the text). If readers are too bogged down in decoding the text, they will not be able to focus on the job of comprehending the author’s message. An example of automaticity in action can be seen in the common skill of learning to ride a bike. Novice bike riders focus so intently on balancing, turning the handlebars, and pedaling that they sometimes fail to attend to other important tasks like direction and potential dangers. Similarly, a reader who is a poor decoder focuses so much of his attention on phonics and other sounding out strategies that he has little brainpower left for comprehending. When this happens, the reading act, like an overloaded computer, “crashes.” In contrast, children who are accomplished bike riders can ride without hands, carry on a conversation with a friend, dodge a pothole in the road, and chew gum at the same time. Like the accomplished bike rider, fluent readers can rapidly focus on the author’s message because decoding no longer demands the lion’s share of their attention capacity. In summary, the LaBerge and Samuels (1974) model predicts that if reading can occur automatically, without too much focus on the decoding process, then improved comprehension will be the result.

Teachers who believe that bottom-up theories fully explain how children become readers often teach subskills first: they begin instruction by introducing letter names and letter sounds, progress to pronouncing whole words, then show students ways of connecting word meanings to comprehend texts. Although bottom-up theories of the reading process explain the decoding part of the reading process rather well, there is certainly more to reading than decoding. To become readers, students must compare their knowledge and background experiences to the text in order to understand the author’s message. Truly, the whole purpose of reading is comprehension.