Concerned with a high failure rate in computer programming courses, two studies were undertaken to discover if two individual cognitive styles--"analytic" (formal thought) and "heuristic" (concrete or pre-operational thought)--were predictors of performance in a beginning computer programming course. To appropriately measure those skills, a Piagetian-based paper and pencil test of cognitive development called "How Is Your Logic?" (HIYL) was administered to a total of 116 undergraduates in three beginning computer programming courses at a small liberal arts college. In the first study of 87 students, 91% who received a course grade of "B+" or higher were formal thinkers, while no one who was classified as concrete operational received a grade higher than a "C+." The correlation between course grades and HIYL was statistically significant. In study two, the performance of 29 students on a pre- and posttest of HIYL was compared with their performance in the course to measure cognitive development during the course; scores on the two forms did not demonstrate measurable development over the 10 weeks of the course. Using a Piagetian framework to analyze the text used by all classes, three major components requiring formal thought were identified--hierarchical classifications of abstract concepts, control structures, and top-down design--and each is discussed. The criteria for classification, weighting components, correlations between HIYL and grades, and correlations between course and test grades are displayed in tabular format. (DJR)