M.Sc Thesis

M.Sc StudentShpigelman Maya
SubjectIllustrations Effect on the Judgments of Comprehension
Regarding Problem Solutions
DepartmentDepartment of Industrial Engineering and Management
Supervisor ASSOCIATE PROF. Rakefet Ackerman
Full Thesis textFull thesis text - English Version


It is widely accepted that well-constructed illustrations promote comprehension of text content. However, the effects of including less well constructed illustrations are not fully understood. Previous research has shown that including uninformative illustrations in expository texts bias the subjective Judgment of COMPrehension (JCOMP) upwards. A first study which challenged students with understanding explanations of solutions for hard logic problems has shown similar results. The present study examined the boundaries of this finding.

Earlier metacognitive studies have found that weak students are more prone to the misleading effects of superficial cues. The present study aimed to examine whether cognitive ability of undergraduate students is the key for overcoming the misleading effects of the inclusion of uninformative illustrations in explanations to logic problems. The participants in the study were engineering students at the Technion with higher SAT scores than previously examined. Beyond the effect of cognitive ability, two additional factors common in everyday life were manipulated. Working under time pressure in Experiment 1 and working on screen in Experiment 2.

The main finding of the study is that despite the high cognitive abilities of the present sample, the results revealed a pronounced effect of the illustrations on success rates and on JCOMP: while JCOMP were raised in the presence of uninformative illustrations, success rates went down, which increased significantly the gap between the subjective assessment of comprehension and applicable knowledge. These findings suggest, as hypnotized, that it is the difficulty of the task, respectively to the cognitive ability, which makes the students susceptible to the misleading effects of the concrete illustrations. Working under mild time pressure did not increase the biasing effect of uninformative illustrations any further. When working on screen, the misleading effect of the inclusion of the uninformative illustrations disappeared. It seems that participants’ experience with selectively ignoring distractive illustrations during their Internet usage made it possible for them to ignore the illustrations, resulting in a significantly shorter study time, higher success rates and smaller gap between judgments of comprehension and performance in comparison to the paper learners of Experiment 1. 

Overall, the results suggest that even among the strongest students the JCOMP is biased upward in the presence of illustrations. This study stresses the harmful potential of ill-constructed illustrations regardless of students’ cognitive abilities, on one side, while introducing a new perspective of conditions for overcoming it, on the other.