Pre- and posttests and interviews concerning misconceptions and alternate conceptions of rates of change were administered to (n=42) students in first-semester calculus using a conceptually-motivated curriculum. Suggests that an emphasis on visual representations through construction and interpretation in conjunction with teacher-student analysis…

Describes attempts to instruct 12 children, aged between 10 and 11, during a 12-hour course in LOGO that proper attention should be paid to the external angles through which the turtle rotated. Results suggest that using LOGO to draw closed figures may lead to confusions about angle that are not amenable to conventional intervention techniques…