Comprehension errors in software design must be detected at their origin to avoid propagation into later portions of the software lifecycle and also the final system. This research synthesizes software engineering and Gestalt principles of similarity, proximity, continuity for the purpose of discovering whether certain visual attributes of diagrams can affect the accuracy and efficiency of understanding the diagram. The experiment tested whether two dependent variables, accuracy and response time, were significantly affected by independent variables, diagram type (simple1, simple2, complex), Gestalt principles (good vs. bad), and question order (forward/backward). The results of this study indicated that the Gestalt principles did affect the comprehension in the complex diagrams. Post-hoc analysis results indicated that number of bends per line, length of line in inches, number of lines crossing, boxes per diagram, and number of lines per diagram contributed to the ability of the subjects to comprehend the diagrams.