Lauren Scharff

Aviation Visual Perception : Research, Misperception and Mishaps

Vision is the dominant sense used by pilots and visual misperception has been identified as the primary contributing factor in numerous aviation mishaps, resulting in hundreds of fatalities and major resource loss. Despite physiological limitations for sensing and perceiving their aviation environment, pilots can often make the required visual judgments with a high degree of accuracy and precision. At the same time, however, visual illusions and misjudgments have been cited as the probable cause of numerous aviation accidents, and in spite of technological and instructional efforts to remedy some of the problems associated with visual perception in aviation, mishaps of this type continue to occur. Clearly, understanding the role of visual perception in aviation is key to improving pilot performance and reducing aviation mishaps. This book is first dedicated to the role of visual perception in aviation, and it provides a comprehensive single-source document encompassing all aspects of aviation visual perception. Thus, this book includes the foundations of visual and vestibular sensation and perception; how visual perceptual abilities are assessed in pilots; the pilots perspective of visual flying; a summary of human factors research on the visual guidance of flying; examples of specific visual and vestibular illusions and misperceptions; mishap analyses from military, commercial and general aviation; and, finally, how this knowledge is being used to better understand visual perception in aviations next generation.

Demonstrating the impact of multitasking in the classroom

The advent of laptops, mobile devices, and ubiquitous connectivity in the classroom has created both opportunities and challenges for the learning environment. Students, often feeling that they are good multitaskers, will use their laptops to read e-mail or browse the web during classes. Telling students the results of multitasking research may convince some students not to become distracted, but experiencing it first-hand provides a more active learning approach to the lesson. The goal of this project was to design a meaningful demonstration of the negative effects of multitasking so that students would internalize the message and, hopefully, change their behavior, if necessary. In this demonstration students were assigned to three groups, one which had no computing distraction (students were asked to take notes on paper), one which had a single on-line distraction, and one group which had dual on-line distractions. All groups were told that distractions should not be allowed to interfere with their class work. At the end of the lecture, students completed a quiz on the material just presented to test their level of understanding. There was a significant effect on quiz performance. The group without distractions obtained higher quiz scores than either distraction group. End-of-semester feedback showed that 63.5% of the students reported modifying their behavior in class based on the demonstration.

The Effect of Small Changes in Web Page Navigation Links on the Performance of Users Who Revisit Sites

This paper examines the results of a study conducted to determine if small changes to a sites primary navigation structure would significantly impact user performance. Between a users first visit and their subsequent revisit a week later, a single task-related link was either consistently present, consistently absent, or was added or removed between the two visits. Results show that performance was significantly degraded when the critical navigation element was removed from the page after the user first visited the site. Additions to the navigational structure were less disruptive to user performance and actually enhanced it because the additional link provided another navigational pathway to the desired information. The one week re-visitation delay produced results similar to those found in a similar study where the delay was less than 5 minutes (Scharff, 2006). Further research is being conducted to determine the between-visit time required in order for performance to be consistent regardless of the link condition.

Interactive tools in the graphics classroom

Computer graphics is a fun course for both teachers and students. The topics are filled with interesting images and animations, there is a wealth of support material available, and students are motivated to express creativity in projects. There are also underlying math concepts and algorithms that some students find challenging to fully understand. At our institution, we teach a computer graphics course to junior and senior-level computer science majors as an elective. To assist their understanding of fundamental concepts and algorithms, we created and employed a collaborative learning approach using locally developed interactive tools during each lecture. The Think-Pair-Share model was used to facilitate collaborative interaction between students. The results of this approach were measured through in-class feedback questions and student performance on individual exam questions. Students enjoyed using the tools, highly rating them on the feedback forms, but were less enthusiastic about the classroom methodology used to present them. These results along with lessons learned will be addressed.

THE IMPACT OF WEB SITE FAMILIARITY ON USER PERFORMANCE WHEN CRITICAL NAVIGATION LINKS CHANGE

The research in this paper examines the effect of web site familiarity on the impact of small changes in a site’s primary navigation structure on user performance. Ninety-two participants performed multiple tasks on a web site, and then returned to the site either immediately or after a three-week delay to perform one of the original tasks again. Half the users had the critical navigation link on the first task, while half did not. On the second visit, the presence or absence of the link either remained consistent, or was the opposite of the condition experienced during their first visit. The addition of multiple tasks during the user’s first visit to the website was expected to cause the memory of the path to the target to be less salient during subsequent visits, thus reducing the performance increase observed in prior studies. However, results show that web site familiarity did not have a significant effect on user performance in this task. One likely explanation for this finding is that there is a trade-off between the salience created for the correct information path gained by performing a single-task first visit and the familiarity gained through multiple forays through the site as the result of multiple task completion.

Where’s My Web Page? How Aesthetic Changes Affect User Performance When Critical Navigation Links Change

This paper reports the results of a study that examined the impact of aesthetic changes to a web site on user performance when a single critical link in the main navigation of the page also changed. 102 participants performed 4 search tasks on a web site. They were then redirected back to the site immediately or waited approximately 14 days to perform the first search task again. Half the participants had the critical navigation link on the first set of tasks, while the other half did not. On their second visit, the presence or absence of the link was either consistent, or was the opposite of what they had encountered on their first visit. In all cases, participants saw a web site with one aesthetic look on their first visit, and this aesthetic was changed for their second visit. Results showed that, while users generally noticed changes to the site after an aesthetic change, they were not particularly good at determining exactly what changed. Further, their ability detect and describe these differences decreased as the time between recurrent visits increased, and for the most part, the changes did not adversely impact objective performance measures.