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The purpose of this thesis is to explore how support systems enable human control within normal flight operations. The thesis focuses on the use of memory supports during flight, such as a handheld computing device, memory strategies and checklists. The support systems are studied from the theoretical perspective of Human Factors. In particular, decision making theories have contributed to the thesis. From previous research it is found that feedback to the operator in case of a human error is essential to keep him or her in a safe sequence of decisions and actions. To facilitate the pilots’ tasks in cockpit, computing devices are out on the market. Several of the technical aids are computers installed in cockpit whereas others are smaller, portable devices with hardware not specifically designed for use in cockpit. Jump-seat observations have been performed at an airline company to explore the pilots’ work process in cockpit where a handheld computing device, with hardware not specifically designed for cockpit, is in use. Subsequent semi-structured interviews were conducted to receive the pilots’ experiences of findings from the observations and to receive descriptions of decisions and support systems. The thesis includes a description of flight operations from a pilot perspective. The main focus is on operations in the preflight phase where the new computing device is used. Identified characteristics in flight operations are factors such as cooperation, communication, interruptions. Furthermore, identified factors in the decision making were such as routine, environmental constraints, discrete alternatives and dependency between decisions. Feedback points during the sequence of tasks performed with the handheld computing device were distinguished. These points are moments when feedback is possible. For example, when the pilots cross-check tasks they receive feedback from each other. It was found that the pilots did not use every opportunity to receive feedback on their performance. The reason of the non-used feedback point was that it was not required by the Standard Operating Procedures or by any functions or design of the device. Within flight operations in general, it was found that the most important techniques to detect a human error such as a memory lapse were by pilots’ earlier experiences, the use of checklists and by receiving feedback from the other pilot. / QC 20101109

Delays in the process of diagnosing and treating cancer are common and lead to confusion and undesirable outcomes. Care coordinators are often embedded within the system of care to manage follow-up care. Electronic and real-time reminder systems can be used to support the care coordinator’s work, but electronic health record (EHR) usability is known to be poor. This study, completed in collaboration with the Department of Veterans Affairs (VA) Connecticut Healthcare System, evaluated the Cancer Coordination and Tracking System (CCTS), an EHR-linked, web-based tool for cancer care management. A set of expert-driven and user-driven usability engineering methods was applied to comprehensively identify and analyze usability problems within the system. Ten current CCTS users were engaged in the study to help identify problem. 101 (62.3%) problems were identified through expert-driven methods, 56 (34.6%) were identified by user-driven methods, and 5 (3.1%) were identified through both types of methods. The list of 162 unique problems were prioritized and twelve high priority problems were highlighted. Design recommendations were developed to address each of these high priority problems.

In the United States, speeding is considered to be a contributing factor in about 30 percent of fatal crashes (US DOT, 2000). In an attempt to reduce speeds on roadway segments where speed is considered to be a safety concern, various low cost countermeasures have been investigated. Such countermeasures include pavement markings that give a psychological appearance of narrowing and/or increasing speed have been considered as a relatively low-cost treatment. Perceptual cues are one potential method of influencing motorists to slow down, and ultimately, to save lives. These perceptual techniques might be useful at lowering speeds in a variety of driving situations such as work zones, curves, roundabouts, and toll plazas. Evaluations are required in order to determine the effectiveness of these various treatments at reducing speeds. This research project explored several possible perceptual countermeasures to try on the approaches to curves for reducing speeds. It was ultimately decided to evaluate the effects of peripheral transverse lines in reducing speeds. Although there have been some limited evaluations of peripheral transverse markings in previous studies, no significant field evaluation has been performed and a recommended design for the markings has not been discussed. The projected results of the research effort is to determine pavement marking treatments with a high probability of success at reducing speeds, develop and design peripheral transverse markings based on site considerations, determine the effectiveness of the markings in the field, determine optimal pavement marking design using a driving simulator, and use a controlled research environment to finalize the design. This dissertation contributes to the body of knowledge on speed reduction research through the development of low cost speed reduction strategies, the design of peripheral transverse lines for varying geometric conditions, evaluation of these treatments in the field, in the simulator, and on a controlled roadway, and to finally compare the benefits of each of the evaluation approaches. In the field, peripheral transverse lines spaced at a frequency of 4 bars per second were evaluated in New York, Mississippi, and Texas. The markings were applied on approaches to curves in both rural and urban environments on both multi-lane and two-lane roadways. The authors concluded that overall, the pavement markings reduced speeds up to 59% compared to the baseline in the short term and 24% in the long term on overall vehicle speeds. When evaluating design alternatives of peripheral transverse markings, a follow-up study was performed and compared baseline conditions to markings spaced at a constant interval, exponentially closer, at two bars per second, and at four bars per second. The peripheral transverse lines were effective in reducing centerline encroachment; however, the results were inconclusive as to which particular marking spacing pattern was most effective. There was a large amount of variability in driving speeds using the driving simulator which made it ineffective at comparing designs. The third evaluation was performed at the Virginia Tech Smart Road in which reductions in speed were compared to the baseline at two locations. While one curve had large preview distances and no effect due to the treatments, speed reductions on a freeway ramp type of curve resulted in a speed reduction 42% greater than the reduction in the baseline condition. There are several advantages and disadvantages to evaluations in the field, simulator, and at a controlled research setting which are summarized in this dissertation. Overall, all three have potential of looking at different elements, but it was determined that variability when measuring speed in the driving simulator makes it more challenging as a tool for measuring speed reductions. / Ph. D.

Understanding how patients and operators trust medical technology will provide insight into the role, implementation and use of technology in health systems. Models developed in aviation and manufacturing that predict operators' trust or distrust in technology (Biros, 2004; Jian, Bisantz, Drury, & Llinas, 1998; Lee & See, 2004; Muir & Moray, 1996; Parasuraman, 1997) may not be applicable to medical technology and health systems. The first objective of this research was to empirically define the construct trust in medical technology by differentiating it from trust in technology and providing a model of it's factors. The second objective of this research was to generate a theory of how patients and health care providers construct trust in medial technology in an applied context. The third objective of this research was to develop and validate an instrument to measure patients' trust in medical technology. The results of these combined studies identified 30 factors of trust in medical technology and provided evidence to support the hypothesis that trust in technology and trust in medical technology are different constructs. A grounded theory was developed that shows that patients' trust in medical technology is based on a combination of characteristics from the technology, providers and how the providers use the technology, while physicians' trust is constructed from the trustworthiness of the system and trust in their own abilities. An 80 item instrument for measuring trust in medical technology was developed and validated. Recommendations for the design of obstetric work systems are discussed. / Ph. D.

Within the home environment there exits a host of digital color imaging (DCI) system configurations. The combination of devices and software at the consumer's desktop with devices and services at a remote location (e.g., Print at Kodak), creates a complex interaction of device, contextual, and observer characteristics. In particular, the cathode-ray tube (CRT) display has the potential to influence consumers' perceptions of image quality and their subsequent image manipulation activities. Depending on the inherent color bias and apparent contrast of the CRT, extensive image manipulation may occur, significantly altering the digital values of the image. Output generated by a remote printer will reflect any image manipulation undertaken by the consumer. If manipulation was extensive, what the consumer receives from a remote printer will appear quite different from the softcopy version and thus, may be deemed unacceptable. This research was designed to address the softcopy-hardcopy matching issues that arise from the home DCI system configuration just described. The primary study examined how the CRT display influenced perceived color quality of photographs generated at two points in a DCI system; on-screen photographs (softcopy) and photographic quality prints (hardcopy). CRT gamma, color temperature, and excitation purity were manipulated using an orthogonal, blocked, central composite design. Twenty-two Eastman Kodak Company employees viewed 6 photographs under each of the 15 CRT conditions. Participants rated the color quality of each softcopy photograph, then were given an opportunity to edit color balance, brightness, and contrast for each photograph. The edited photos were printed and rated once again for color quality and acceptability. Results indicated that monitor calibration influenced perceived softcopy color quality, softcopy editing behavior, and subsequent perceived hardcopy color quality. Perception of softcopy color quality ratings was determined predominantly by the CRT gamma level. Participants responded to CRT color balance differences through their editing behavior. In some cases, edits were large enough to significantly and negatively impact perceived hardcopy color quality. Gamma in particular, was the most significant predictor of hardcopy color quality ratings and rejection rates. Additional differences were observed between first- and third-party photographs. Results from this research may be applied to the development of monitor calibration tools, scene balancing algorithms, and software, for the purpose of accommodating consumer image manipulation behavior, in the context of the home DCI system presented herein. / Ph. D.

As the frontiers and futures of work evolve, humans and machines will begin to share a more cooperative working space where collaboration occurs freely amongst the constituent members. To this end, it is then necessary to determine how information should flow amongst team members to allow for the efficient sharing and accurate interpretation of information between humans and machines. Shared situation awareness (SSA), the degree to which individuals can access and interpret information from sources other than themselves, is a useful framework from which to build design guidelines for the aforementioned information exchange. In this work, we present initial Augmented/virtual reality (AR/VR) design principles for shared situation awareness that can help designers both (1) design efficacious interfaces based on these fundamental principles, and (2) evaluate the effectiveness of candidate interface designs based on measurement tools we created via a scoping literature review. This work achieves these goals with focused studies that 1) show the importance of SSA in augmented reality-supported tasks, 2) describe design guidelines and measurement tools necessary to support SSA, and 3) validate the guidelines and measurement tools with a targeted user study that employs an SSA-derived AR interface to confirm the guidelines distilled from the literature review. / Doctor of Philosophy / As the way in which humans work and play changes, people and machines will need to work together in shared spaces where team members rely on one another to complete goals. To make this interaction happen in ways that benefit both humans and machines, we will need to figure out the best way for information to flow between team members, including both humans and machines. Shared situation awareness (SSA) is a helpful concept that allows us to understand how people can get and understand information from sources other than themselves. In this research, we present some basic ideas for designing augmented reality (AR) tools that help people work together in better ways using SSA as a guiding framework. These ideas can help designers (1) create AR tools that work well based on these basic ideas and (2) test how well different interface designs work using specially developed tools we made. We completed user studies to (1) show how important SSA is when using AR to help with tasks, (2) explain the design ideas and tools needed to support SSA, and (3) test these ideas and tools with a study that uses an AR tool, based on SSA, to make sure the guidelines we got from reading other research are correct.

Improving the safety of medicines management when people leave hospital is an international priority. There is evidence that poor co-ordination of medicines between providers can cause preventable harm to patients, yet there is insufficient evidence of the structure and function of the medicines management system that patients experience. This research used a mixed-methods social network analysis to determine the structure, content and function of that system as experienced by patients. Patients’ networks comprised a range of loosely connected healthcare professionals in different organisations and informal, personal contacts. Networks performed multiple functions, including health condition management, and orienting patients concerning their medicines. Some patients experienced safety incidents as a function of their networks. Staff discharging patients from hospital were also observed. Contributory factors that were found to risk the safety of patients’ discharge with medicines included active failures, individual factors and local working conditions. System defences involving staff and patients were also observed. The study identified how patients often co-ordinated a system that lacked personalisation and there is a need to provide more consistent support for patients’ self-management of medicines after they leave hospital. This could be achieved through interventions that include patients’ informal contacts in supporting their medicines use, enhancing their resilience to preventable harm, and developing and testing the role of a ‘medicines key worker’ in safely managing the transfer of care. The role of GP practices in co-ordinating the involvement of multiple professionals in patient polypharmacy needs to be further explored. / University of Bradford studentship

In the modern computing landscape, the challenge of tuning software systems is exacerbated by the necessity to accommodate multiple divergent execution environments and stakeholders. Achieving optimal performance requires a different configuration for every combination of hardware setups and business requirements. In addition, the state of the art in system tuning can involve complex statistical models and tools which require deep expertise not commonly possessed by the average software engineer. As an alternative approach to performance tuning, this thesis puts forward the use of sonification-conveying information via non-speech audio-to aid software engineers in tuning complex systems. In particular, this thesis designs, develops, and evaluates a tuning system that interactively (i.e., in response to user actions) sonifies the performance metrics of a computer system. This thesis demonstrates that interactive sonification can effectively guide software engineers through performance tuning of a computer system. To that end, a scientific survey determined which sound characteristics (e.g., loudness, panning, pitch, tempo, etc.) are best suited to express information to the engineer. These characteristics were used to create a proof-of-concept tuning system that was applied to tune the parameters of a real world enterprise application server. Equipped with the tuning system, engineers-not experts in enterprise computing nor performance tuning-were able to tune the server, so that its resulting performance surpasses that exhibited under the standard configuration. The results indicate that sound-based tuning approaches can provide valuable solutions to the challenges of configuring complex computer systems. / Master of Science