COMPARING EFFECTIVENESS OF GESTALT LAWS IN DIGITAL AND PRINTED INFORMATION GRAPHICS USING EYE TRACKING METHODS

Dealing with complex instructional materials requires a lot of effort by the readers to comprehend and form a mental model of the context. Information graphics is an important visual representation that has the ability to improve comprehension of complex information by revealing trends and reducing the cognitive load of the readers. However, it is essential to follow certain laws to ensure efficiency of the information graphics design. The Gestalt laws of perceptual organization is fundamental to predict how people perceive information. This study tries to investigate the implementation of Gestalt laws of “good continuity”, “connectedness” and “closure” in the design of digital and printed information graphics and their effectiveness in the comprehension and reduction of the cognitive load of the readers. The main goal is to understand how the learners take advantage from information graphics. In order to achieve this goal and measure the cognitive load of the readers, two separate experiments were conducted using eye-tracking devices. Each one of the experiments included four different tasks, with two tasks presented on computer monitor (digital media) and the other two presented on printed posters (printed media). The tasks were randomly assigned to 22 participants all from the same class with roughly the same age group and same nationality. After each task, the participants were asked to answer a set of comprehension questions related to the task. Finally, in the analysis phase, the variations in cognitive load of the participants during completion of tasks was measured by the aid of recorded gaze data (such as the dilation of the pupil size, blinks rate and acceleration of the saccades). The comprehension test results and the estimated cognitive load of the participants were used to calculate the efficiency index for each one of the materials by an artificial neural network classification method. Accordingly, the efficiency index indicates the importance and effectiveness of each one of Gestalt laws applied in the design of materials. Besides the results of the cognitive load analyses, the scan-path of the eyes movements, number of areas-of-interest (AOI) hits, average dwell time, average saccade length and AOI sequence of the participants were also used to identify effect of each one of the applied Gestalt laws. Managing the design principles is a crucial concern for the development of effective instructional information graphics and particularly, findings of this study can be applied for layout design strategies. The main purpose of designing information graphics is to minimize the amount of cognitive effort required to understand the context. The results of this study demonstrates how laws of “good continuity”, “connectedness” and “closure” can improve the comprehension and effectively reduce the cognitive load of the participants.