All too often educators establish a "pretest, skill, posttest" type of curriculum. While this approach has an educational value, it must be used within a developmental framework based on individual thinking and learning style. Thus, a thorough knowledge of cognitive development is necessary. A review of the body of knowledge concerning individual learning style suggests some implications for practice. The aim of the following review is to provide an introduction to that body of knowledge and to suggest some implications for practice. The preoperational stage of development, as described by Jean Piaget, is especially important to early childhood and elementary educators, since a majority of children are preoperational at the time formal schooling is begun. A complete discussion of cognition requires recognition of individual differences in the learning process. Investigations of the manner in which cognitive functions are executed, or of cognitive style, attempt to identify individual differences in the way children think, perceive, remember, and gather and use information. Two dimensions of cognitive style have been studied: reflective/impulsive and field-dependent/field-independent responses. Cognitive theory in general suggests implications for establishing the classroom as a learning environment based on an activity-oriented curriculum as well as for selecting developmentally appropriate reading and arithmetic materials. (Sample lesson plan objectives and activities for children with developmental reading problems are appended.) (RH)