Using visual models is common in science and should become more common in classrooms. Our research group has developed and completed studies on the use of a visual modeling tool, the Concept Connector. This modeling tool consists of an online concept mapping Java applet that has automatic scoring functions we refer to as Robograder. The Concept Connector enables students in large introductory science courses to visualize their thinking through online model building. The Concept Connector's flexible scoring system, based on tested grading schemes as well as instructor input, has enabled greater than 1,000 physiology students to build maps of their ideas about plant and animal physiology with the guidance of automatic and immediate online scoring of homework. Criterion concept maps developed by instructors in this project contain numerous expert-generated or "correct" propositions connecting two concept words together with a linking phrase. In this study, holistic algorithms were used to test automated methods of scoring concept maps that might work as well as a human grader. (Contains 4 figures and 2 tables.)