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Software development is an endless problem-solving activity and programmers regularly use online media channels to ask each other for advice. In particular, socially enabled media channels like the question & answer website Stack Overflow changed how programmers communicate and coordinate, and how they produce and consume content on the Web. Nowadays, a vast body of software development knowledge is documented in form of code examples. But acquiring the knowledge by reading code and logically reason about how they work makes non-trivial examples hard to understand. The aim of this work is to develop visual enhancements that support programmers in the knowledge exchange with code examples. Through a design science research approach using interaction design methods visualizations were developed and evaluated that allow programmers to see the execution and simultaneously inspect the state in order to gain a better understanding of how the underlying system of the code example works. Professional programmers participated in a workshop and found the visualizations to be helpful in the comprehension process.

<p dir="ltr">Task performance is considered an important emphasis in the world of Human-Computer Interaction (HCI). With the emergence of advanced technologies such as Virtual Reality (VR), it is important to understand how individuals are able to utilize this tool for productive task performance. Researchers are continuously exploring how to enhance human performance in a digital space (Wang & Jung, 2011). Prior research has demonstrated the role of integrating haptic feedback into a visual interface, with potential benefits in task performance, as well as increased experiences of presence and awareness while completing HCI tasks. Several research studies have been carried out to investigate ways to optimize human performance and richly uncover factors that affect human performance negatively and positively (Asan et al., 2015). Typically, in a VR setting, three primary senses are engaged: visual, auditory, and tactile (haptic). However, there is a gap in the literature regarding how the availability and intensity of haptic feedback through VR controllers affect users during task performance. This research study seeks to understand the cognitive performance of users in VR when exposed to varying levels of haptic feedback via the VR controllers. Results from this research reveal that participants perceived their performance to be higher and frustration to be lower when they were exposed to moderate and consistent availability and intensity of haptic feedback. To enhance VR’s immersion for users, it is essential to comprehend how to engage the human senses to optimize cognitive performance. Overall, the impact of this research study is to add to an existing body of literature in the domain of haptic feedback for extended reality-based experiences. </p>

Motor vehicle crashes are a leading cause of death during adolescence, with the fatal crash rate per mile-driven for 16-19 years old drivers being nearly 3 times larger than the rate for drivers age 20 and older. High gravitational events among teenage drivers, such as quick starts, and hard stops, have been shown to be highly correlated with crash rates. The current younger driver training programs developed in the late 1990s, however, do not appear to be especially effective in regard to many skills which are critical to avoiding crashes. With this in mind, a simulator-based training program aimed at reducing the behaviors that make quick accelerations unsafe and quick decelerations unnecessary was designed and evaluated. The training adopts the active training strategy which has been proven to be effective, and includes those scenarios in which teenage drivers are at highest risks. It is expected that drivers who receive the active training will drive more safely than drivers who receive the placebo training, in terms of eye scanning behaviors in scenarios where quick accelerations are necessary (e.g., how often they glance towards areas where threats could emerge), following behaviors in scenarios where a lead vehicle could stop suddenly (e.g., how much headway they allow between their vehicle and a lead vehicle), and vehicle behaviors such as speed, acceleration rate, deceleration rate and headway.

This project is an in-depth investigation on the impact of lighting, marking and paint schemes on the operational aspects of police vehicles. This investigation consisted of two phases that ultimately consisted of four experiments. An array of lighting and marking schemes were implemented on police vehicles in a variety of jurisdictions for evaluation. The study then investigated the change in the visibility of police officers, the public reaction to these schemes, and the operational impacts of these systems. The first phase of the project was a naturalistic observation study where the goal was to better understand how traffic behaved around traffic stops. Test vehicles were positioned in simulated traffic stops and patrol locations to determine how traffic behavior was affected by various configurations of police lighting and markings. Camera and radar systems were used to measure the changes in driver speed and when drivers responded to the move over law. Based on the results of the naturalistic studies, the impact of the lighting system on officer visibility was investigated in a controlled human factors test where the ability of a driver to see a police officer outside of their vehicle was measured in the presence of the lighting systems. The purpose of this interjected effort was to verify that the experimental schemes would not increase risk to law enforcement despite data from the first phase indicating the vehicles were more visible. A second part to that study evaluated conventional methods of bolstering an officer's visibility outside of their vehicle at night. The second phase took the findings of the first phase and implemented changes to several police vehicles from local and state agencies to be in operation for at least 18 months. This was to assess the rate of near-misses and crash rate to relate the vehicle changes to law enforcement safety. Additionally, rates of citations were assessed, and surveys offered an opportunity for law enforcement to provide their own feedback on the implementations. The lighting systems evaluated included a completely blue lighting system, an enhanced all blue lighting system with twice the light output, a red and blue system, and a single flashing blue beacon. In terms of markings, retroreflective markings along the side of the vehicle, a retroreflective contour line, chevrons on the rear of the vehicle and unmarked vehicles were evaluated. Finally, a variety of vehicle colors were used to investigate the impact of the base vehicle paint color. The results indicate that both the red and blue lighting system and the high output blue lighting system increase the distance at which drivers moved over significantly. In general, at least 95% of traffic attempted to merge away from an actively lighted police vehicle, when possible. In terms of the speed change, drivers began reducing their speed by approximately 600 m from the police vehicle. Similarly, the addition of retroreflectivity to the rear of the vehicle showed an additional benefit for causing drivers to move over sooner. However, these benefits came at a cost to the officer's visibility. When outside of their vehicle, the high output blue system significantly reduced officer detectability while the red and blue configuration only impacted detection distance by 3 meters. The investigation did find that these impacts could be overcome with retroreflective vests worn by the officers. In the second phase, a preference revealed by officers favored the red-blue configuration. They stated that this configuration provided greater comfort for them and less glare to approaching drivers. The study also revealed that the alternative configurations did not impact the operational activities of police authority. / Doctor of Philosophy / This project evaluated how lighting, marking and paint schemes on police vehicles affected their visibility and how traffic responded to them. An observational study positioned police vehicles with alternative lighting and markings in simulated traffic stops and patrol locations to evaluate traffic behavior. Camera and radar systems were used to measure the changes in driver speed and when drivers responded to the Move Over law. A second study evaluated how the lighting systems on a police car affect the visibility of an officer at night in a traffic stop scenario. A followup experiment looked into methods for bolstering the visibility of officers at night through conventional implementations such as body worn LED lighting, the use of a retroreflective vest, or by using lighting on the police vehicle's light bar to increase illumination of the police officer. A third study took the findings of the previous experiments and outfitted 64 Virginia State Police vehicles for 18 months. Another 64 Virginia State Police vehicles participated in a control condition where no changes were made to their vehicles. Data collected included the rate of near-misses or crashes and the rates of written citations. Surveys were administered to each participating officer regarding their perception of safety and comfort and allowed their open feedback and suggestions. The lighting systems evaluated included a completely blue lighting system, an enhanced all blue lighting system with twice the light output, a red and blue system, and a single flashing blue beacon. In terms of markings, retroreflective markings along the side of the vehicle, a retroreflective contour line, chevrons on the rear of the vehicle, and unmarked vehicles were evaluated. Finally, a variety of vehicle colors were used to investigate the impact of the base vehicle paint color. The results indicate that both the red and blue lighting system and the high output blue lighting system increase the distance at which drivers moved over significantly. In general, at least 95% of traffic attempted to merge away from an actively lighted police vehicle, when possible. In terms of the speed change, drivers began reducing their speed by approximately 600 m from the police vehicle. Similarly, the addition of retroreflectivity to the rear of the vehicle showed an additional benefit for causing drivers to move over sooner. However, these benefits came at a cost to the officer's visibility. When outside of their vehicle, the high output blue system significantly reduced officer detectability while the red and blue configuration only impacted detection distance by 3 meters. The investigation did find that these impacts could be overcome with retroreflective vests worn by the officers. In the second phase, a preference revealed by officers favored the red-blue configuration. They stated that this configuration provided greater comfort for them and less glare to approaching drivers. The study also revealed that the alternative configurations did not impact the rate of citations.

Zur Beurteilung der Rolle von menschlichen Faktoren bei Eisenbahnunfällen wurden 41 Untersuchungsberichte der Bundesstelle für Eisenbahnunfalluntersuchung einer strukturierten Inhaltsanalyse unterzogen und die Handlungen von Fahrdienstleitern (Fdl) und Triebfahrzeugführern (Tf) in Kategorien zu Fehlerklassifikationen nach Reason und Ebenen des Situationsbewusstseins nach Endsley eingeteilt. Darauf aufbauend wurden Hypothesen abgeleitet, welche in einem Online-Fragebogen untersucht wurden. Es wurde dabei mit Einstichproben t-Tests gegen durch Expertenwissen definierte Cutoff-Werte festgestellt, dass das Sicherheitsklima unter Fdl und Tf niedrig ist, dass Fdl Fahrstraßen zu früh auflösen, dass Fdl Hilfssperren bewusst nicht immer anbringen, dass Fdl Fahrwegprüfungen durch Hinsehen nicht mit angemessener Sorgfalt durchführen, dass Tf sich nach Zwangsbremsungen nicht an die Vorgaben halten, dass Tf nicht alle für sie geltenden Signale wahrnehmen und dass Tf bewusst schneller als erlaubt fahren. Mit einem Zweistichproben-t-Test wurde getestet, ob die meisten Fehler von Fdl und Tf auf der Ebene der Wahrnehmung nach Endsley im Vergleich zu den Ebenen des Verständnisses und der Projektion passieren, lieferte aber kein signifikantes Ergebnis. Es konnte herausgearbeitet werden, dass in Deutschland im Bereich der Unfallanalyse Verbesserungspotenziale bestehen und sich dabei an anderen Hochrisikobranchen orientiert werden kann.:1 Motivation ........................................................................................................... 9 2 Theorie: Fehler und Sicherheit im System Bahn .......................................... 10 2.1 Fehlerdefinition nach Reason................................................................ 10 2.2 Situationsbewusstsein nach Endsley.................................................... 12 2.3 Theorie der wissenschaftlichen Fragebogenerstellung und Statistischen Analyse.............................................................................. 13 2.4 Sicherheitskultur und Sicherheitsklima............................................... 15 2.5 Sicherheit im System Bahn .................................................................... 16 2.6 Bedeutung des Menschen im System Bahn ......................................... 17 2.7 Abstraktionen von Sicherheit und Fehlern im System Bahn............. 19 2.8 Selbstschutz vor Fehlern ........................................................................ 21 2.9 Ziel der Untersuchungsberichte der Bundesstelle für Eisenbahnunfalluntersuchung (BEU).................................................... 22 3 Methodik dieser Arbeit.................................................................................... 24 3.1 Vorgehen .................................................................................................. 24 3.2 Ergebnisse der Analyse ........................................................................... 27 3.2.1 Auswertung nach Reason ................................................................ 28 3.2.2 Auswertung Situationsbewusstsein ................................................ 31 3.2.3 Mangelhafte Fahrwegprüfung ......................................................... 32 3.2.4 Unzeitiges Umstellen von Weichen................................................. 33 3.2.5 Hilfssperren....................................................................................... 34 3.2.6 Kommunikation, Funkdisziplin, Team-SA und Notrufe ................. 35 3.2.7 Frühzeitiges Auflösen von Fahrstraßen .......................................... 38 3.2.8 Geschwindigkeitsüberschreitungen................................................ 38 3.2.9 Verhalten von Tf nach Zwangsbremsungen................................... 39 3.2.10 Wahrnehmung von und Vorbeifahrt an Halt zeigenden Signalen 40 3.2.11 Auswertung der Zwischenberichte.................................................. 40 3.2.12 Einsatzdauer auf dem Stellwerk als Kriterium für die Wahrscheinlichkeit einer unsicheren Handlung ............................ 41 3.2.13 Sicherheitsklima................................................................................ 41 4 Fragebogenerstellung ...................................................................................... 42 4.1 Hypothesenbildung................................................................................. 42 4.2 Frageformen und Antwortmöglichkeiten ............................................ 42 4.3 Ablauf der Befragung.............................................................................. 43 4.4 Anzahl der Items pro Hypothese........................................................... 44 4.5 Rekrutierung............................................................................................ 44 4.6 Beschreibung der Stichprobe................................................................. 46 4.7 Gütekriterien des Fragebogens ............................................................. 47 4.7.1 Bewertung der Objektivität.............................................................. 47 4.7.2 Bewertung der Reliabilität................................................................ 47 4.7.3 Bewertung der Validität.................................................................... 49 4.8 Vorgehen zur Auswertung der Hypothesen......................................... 50 4.9 Bestimmung der Cutoff-Werte .............................................................. 50 5 Auswertung Fragebogen.................................................................................. 53 6 Diskussion der Ergebnisse............................................................................... 56 6.1 Handlungen von Fdl ................................................................................ 56 6.1.1 Frühzeitiges Auflösen von Fahrstraßen .......................................... 56 6.1.2 Hilfssperren....................................................................................... 56 6.1.3 Fahrwegprüfungen durch Hinsehen ............................................... 57 6.2 Handlungen von Tf .................................................................................. 58 6.2.1 Wahrnehmung von Signalen ........................................................... 58 6.3 Sicherheitsklima...................................................................................... 59 6.4 Regeln zur Selbstüberwachung ............................................................. 60 6.5 Fehler auf der Wahrnehmungsebene ................................................... 60 6.6 Weitere Analysebereiche ....................................................................... 60 6.6.1 Störungsmeldungen bei Alttechnik................................................. 60 6.6.2 Verstöße im ESTW............................................................................. 61 6.7 Bewertung der Datengrundlage............................................................ 61 7 Fazit .................................................................................................................... 65

This research study focused on the development and subsequent evaluation of an in-vehicle Active Traffic and Demand Management (ATDM) system deployed on I-66. The ATDM elements inside the vehicle allowed drivers to remain consistently aware of traffic conditions and roadway requirements even if external signage was inaccessible. Forty participants were accompanied by a member of the research team and experienced the following features from the in-vehicle device (IVD): 1) dynamic speed limits, 2) dynamic lane use/shoulder control, 3) High Occupancy Vehicle (HOV) restrictions, and 4) variable message signs (VMS). This system was equipped with auditory and visual alerts to notify the driver when relevant information was updated. The research questions addressed distraction, desirability, and driver behavior associated with the system. Participant data was collected from the instrumented vehicle, various surveys, and researcher observation. Analysis of Variance (ANOVA) and Tukey-Kramer tests were performed to analyze participant eye glance durations towards the IVD and instrument cluster. Wilcoxon signed rank tests were used to draw conclusions from participant speed data and some survey responses. Several key findings were uncovered related to each research category: 1) the IVD would not be classified as a distraction according to NHTSA distraction guidelines, 2) seventy-three percent of participants would want the in-vehicle technology in their next vehicle, and 3) the speed limit alert motivated participants to alter their speed (based on both survey results and actual participant speed data). / Master of Science

One idea common in the computer industry today is that by the time a technological innovation reaches the mass market it is already obsolete. News of recent technological developments race quickly through the computer industry, creating large scale competition among various businesses for the dollars of both educational institutions and industries. In an effort to produce sophisticated and powerful software readily accessible to users whose area of expertise is not programming, software developers have increasingly turned toward the simplest form of language and concept representation--the icon. As icons become increasingly sophisticated and their function grows, so will their availability in various interfaces. The number of users who operate them will also increase. Advanced help systems and animation will assist in relieving some difficulties while creating others. In either case, icon recognizability will be a crucial factor for anyone (novice or expert) who will use them. The purpose of this study was to verify whether all users unfamiliar with a graphical user interface (GUI) system, specifically icons, will require assistance with 40' "W those icons that are unrecognizable in either form or function. Based on the results of this study, an icon recognizability does exist among different groups of computer users. This recognizability is based upon the experience of the users and not upon the type of software they may use most often.

The joint Simon task is a cognitive reaction time task used to assess shared representations and self-other integration when performing a collaborative task with a partner. However, it is unclear if the underlying mechanisms are specific to representing spatial information or are more general. The objective of the current study was to assess a nonspatial joint Simon compatibility effect. Participants completed the joint Simon task with a partner while seated side-by-side, face-to-face, back-to-back, or with their partner not in the room. They completed the task three times, once with horizontal stimuli (left/right of center), once with vertical stimuli (above/below center), and once with central stimuli (at center). In the central task, compatibility was in color where participant responses (assigned red or green response buttons and gloves) were compatible or incompatible to the stimuli (colored red or green). Results showed no significant compatibility effect for any task in any response orientation condition, indicating no evidence of a nonspatial compatibility effect. Results even failed to replicate the standard joint Simon effect of a spatial compatibility effect in the horizontal task when seated side-by-side. However, exploratory analyses showed a significant nonspatial color compatibility effect in the central task for those assigned green in the side-by-side condition only, indicating that the presence of color in the participants' response (i.e., colored responses button and gloves) may have interfered with representing spatial information. This finding has implications for both theory and application of the joint Simon task, indicating it is sensitive to small changes, occurs for features besides location, and may be most effective when seated side-by-side. Additionally, the broader implications for the cognitive and practical study of joint action show the importance of how different features influence shared representations, how different colors are perceived and represented, and how different response orientations influence performance.