Teachers' concern with the "what" of reading has clouded the issue of the "how" of reading. Knowledge of how a child goes about particular reading tasks may give clues to the difficulties he is encountering. Work with disabled readers during three phases of behavior--(1) before the breakthrough in acquiring a reading process, (2) at the time of the breakthrough, and (3) after the breakthrough--provides insight into how a reading process is acquired. From these observations it is hypothesized that learning how to read occurs in moments of "light." As a child instantaneously perceives a concept which has hitherto eluded him, he acquires a new processing method for making the printed symbol meaningful. Examples of times when a child acquires a new processing method are when he first (1) blends sounds into words, (2) groups printed words into meaningful phrases, and (3) comprehends unvocalized thought units. Since these processes can be acquired independently of one another, children differ in how they read. The teacher who subscribes to this theory will be constantly examining the child's performance to determine whether, in relation to the skill being taught, he understands the process, needs more information, or is ready to use and perfect his skill through functional reading. References are included. (DH)