Interactive Effects of Prior Mathematics Preparation and Level of Instructional Support in College Calculus

A quasi-experimental design was used to investigate aptitude-treatment interaction in conditions of high instructional support (Personalized System of Instruction) and low instructional support (Lecture). A test for the homogeneity of regression coefficients indicated a significant (p <. 01) prior mathematics preparation x level of instructional support interaction. The most dramatic differences in post-course achievement favoring the high instructional support condition accrued to those students at the relatively lowest levels of prior mathematics preparation. Moreover, as level of prior mathematics preparation increased, the achievement differences between levels of instructional support tended to decrease. A verification analysis conducted on a separate sample yielded essentially the same interactive effect.