This study investigated the effects of computer and noncomputer environments on leaming of geometric motions. Two treatment groups, one of which used specially designed Logo computer environments, and one of which used manipulatives and paper and pencil, received eight lessons on geometric motions. Interviews revealed that both treatment groups, especially the Logo group, performed at a higher level of geometric thinking than did a control group. Both treatment groups outperformed the control group on immediate and delayed posttests; though the two treatment groups did not significantly differ on the immediate posttest, the Logo group outperformed the nonLogo group on the delayed posttest. Thus, there was support for the effectiveness of the curriculum and for the notion that the Logo-based version enhanced the construction of higher-level conceptualizations of motion geometry.The major focus of standard elementary school geometry curricula is on recognizing and naming geometric shapes, writing the proper symbolism for simple geometric concepts, and using formulas in geometric measurement. Too often