This study investigated the variation of meaning that may be assigned by students to instructional symbol systems. Toward this end, student interpretations of symbols employed to represent free fall in Boxer, a computational environment designed for innovative instructional activities in math and science, were analyzed. Four classes of…

Describes the implementation of a trajectory-plotting program for a microcomputer; shows how it may be used to demonstrate the focusing effect of a simple electrostatic lens. The computer program is listed and diagrams are included that show comparisons of trajectories of negative charges in the vicinity of positive charges. (TW)

Discusses chaotic behavior (movement) in a nonlinear system using LOGO programs. Presents several examples with program listings. (MVL)