A study is presented which concentrates on the development of a cognitive style assessment instrument for 3- to 8-year-olds and on a series of studies designed to evaluate the role of stylistic and attentional processes in the development of various competencies in young children. This report incorporates a manual for users, a technical report on the Kansas Reflection-Impulsivity Scale for Preschoolers (KRISP) for other researchers, including inter-form, test-retest, and intertester reliabilities, age and sex differences, a one-year stability study, and a study of retardate performance on the KRISP. The fifth section of this report contains two completed studies of attending behavior in young children. The sixth describes five studies concerned with elucidating the development of attention or observing strategies as preverbal aids to young children's learning. A seventh section describes four studies in the planning stages designed to extend the findings of this program. (Author/CK)