Spatial perspectives in text-graphics and reader's mental models: Testing the efficacy of surgical procedural instruction for patients

Text and graphics designed for complex procedural instructions have often proved to be insufficient for the reader to visualize the entire process. This dissertation considered patient education modules that show surgical processes to potential patients. When static graphics are used to demonstrate complex sequential procedural steps in a surgery process, most of the movements in graphical components between steps, from their source to final position, are left on the reader to mentally animate. The movement and addition/removal of graphical components in space from one surgical graphic to another makes mental animation for the reader increasingly difficult. As part of this project I considered two major graphical problems; (1) designing graphics to show how external metallic components fit into biological systems; and (2) how surgical instruments coordinate during surgery. To fill in the visualization problem in graphics due to steps not shown, I tested with two different perspectives in text support: route and survey. While the survey perspective identified objects as relative positions in the environment, the route perspective showed movements through the environment adopting the reader's perspective. Based on previous research findings under similar testing conditions, I hypothesized that the route perspective in text would work better when combined with survey perspective in graphics. Fifty participants were tested. Test subjects were shown text and static graphics involving reconstructive knee surgery. Subjects were asked to judge how artificial knee-joint replacement parts will be located and surgical instruments used after a step described in text and shown by graphics. My results have shown with statistical significance that the ability of the reader to comprehend an intricate procedural action in surgery varies with learning styles along with different textual orientations and graphics presentation. Neither route nor survey perspective proved to be consistently better among all test trials. Overall, survey perspective worked better than route perspective in text. I expected route-based text to be more efficient but the data showed the opposite to be true. Further, one group of participants emerged as better performers than the other group. Importantly, readers did not show any practice effect. Finally, readers did not show any correlation between self-reported difficulty and actual accuracy.