Cognitive style research is hindered by a variety of poorly described measures and style classifications and the use of small samples. This study describes and compares three measures of three postulated dimensions of cognitive style: impulsivity/reflectivity; internal/external locus of control; and field dependence/field independence to determine (1) the shape and characteristics of the score distributions yielded by each measure, (2) the reliability of each measure, and (3) the psychometric characteristics of each test item using a 274-subject-sample of seventh grade students. Results are discussed with respect to each measure and conclusions are offered concerning the utility of each instrument in cognitive style research. (Author/MV)