Algorithm visualization systems and techniques have been introduced in a number of curricula to increase learner engagement and improve pedagogical processes. Effective visualization tools must be educationally beneficial to the learner while avoiding excessive overhead. In an introductory IT course, we compared the effectiveness of a COTS diagramming tool to RAPTOR, a visual programming environment based on flowcharts. Our results indicate the COTS diagramming tool was overly heavyweight and cumbersome. Students using RAPTOR became more actively engaged in developing algorithms.Further, we discovered that introductory IT students who had been introduced to RAPTOR performed better on the final exam than those who had only used the COTS tool. Additionally, these students overwhelmingly preferred RAPTOR to the COTS tool, and indicated that using RAPTOR made it easier for them to develop Java programs. Based on these results, we will use RAPTOR for all sections of the course starting this fall.