Traditionally, studies of beginning reading have focused either on between-subjects' differences or on changes in reading performance characteristics induced by specific training procedures. A third approach to reading is a within-subjects' comparison of individual performance characteristics at varying difficulty levels. The present study investigated the effect of text difficulty level on types of reading errors and the relationship of cognitive style to those effects. Tape recordings were made of elementary school children reading texts at a variety of difficulty levels. Tests were also administered to measure reading achievement and cognitive style. The children's strategies when confronted with difficult material seemed to indicate that a fluent reader switches reading strategies freely to adapt to differing demands of various reading tasks, and that this ability may well be largely a function of general psychological parameters such as cognitive styles. A reading model was constructed, within the framework of Pascual-Leone's and Rumelhart's theories of cognition, which incorporates as an important factor the ability to shift reading strategies. At least three cognitive styles can be identified: adaptive flexibility, impulsivity-reflection, and field dependence-independence. This type of research places reading within a broad cognitive processing framework and may provide curriculum developers and teachers with a more complete understanding of the process they are trying to teach. (Author/AM)