Falls are a major contributor to construction-related fatalities. Many construction fall fatalities occur during roofing, and may be prevented by proper use of fall protection. A prevalent option for fall protection is a personal fall arrest system (PFAS). However, full adaption of PFAS is hindered by usability issues, particularly in the harness component. Current research aims to develop design requirements for more usable fall arrest harness. A study was conducted to consider the inter-relations of objective measures of fit and strap pressure, along with subjective usability measures including discomfort ratings and post-task questionnaire responses. 18 local roofers were recruited to test three different harnesses, while performing both quiet calibration-oriented trials and simulated roofing tasks. Significant correlations between discomfort ratings and pressure values were found only in quiet trials. Questionnaire responses were validated by inter-correlations and by significant correlations with discomfort ratings. Multiple comparisons of objective fit values and questionnaire responses revealed deficits in the low-end harness, while suggesting few differences between the mid- and high-range harnesses. Results from analysis of both objective and subjective measures were considered alongside free-response prompts to develop a set of four requirements for consideration in future harness design, including a lowered harness weight, an intermediate level of padding, inclusion of rolling style vertical strap quick-adjusters, a belt-style thigh strap adjustment mechanism, and the adoption of a three-sized sizing scheme. / Master of Science

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This dissertation explores patient trust in their physician and its impact on telemedicine. Telemedicine is using any technology to remotely communicate with a healthcare professional. The first study explores patient trust in their physician by validating the Wake Forest Trust in Physician scale for use in telemedicine research. The original (TIP) scale consists of 10 items and measures four of the five dimensions of trust: Fidelity, Competence, Honesty, and Global Trust. The final validated scale for telemedicine use (T-TIP) consisted of 12 items measuring three subscales: trustworthiness, interpersonal skills, and confidentiality. Study two explores the relationship between patient trust and delivery mode (telemedicine versus traditional interactions). The results from Study 2 indicate that patients trust their physician more in the telemedicine interaction than in the traditional interaction. There was also an effect of location, ethnicity, and frequency of doctor visits on patient trust. Study three delves further into the relationship between patient trust and telemedicine by examining the impact of communication mode on patient trust. Additionally, study three explores the relationship between usability and trust. There was no difference in patient trust scores between text and verbal communication. However, study three did find that as perceived usability of the interface increases, patient trust in their physician also increases. Also, this study found that the text interface had a higher fixation rate and shorter fixation duration than the video interface, indicating that the text interface had less cognitive load. These studies not only provide a tool for measuring patient trust in their telemedicine physician but also demonstrate that there is an impact of patient trust on telemedicine. The fact that patient trust in their physician is higher in telemedicine means that telemedicine could be used to increase patient participation in their own healthcare. Additionally, the relationship between usability and patient trust could be used to increase telemedicine use.

This research introduces the concept of transferability into the usability construct and creates the Usability Paradigm for Multiple Device System (UPMDS) to conceptualize and quantify the usability in multiple device scenarios. This study fills the literature gap that no effective method exists in measuring transferability and in quantifying usability in a multiple device context. This study also answers the research questions regarding the impact of task complexity, user experience, and device order on the total usability of the system. Study one follows a systematic approach to develop, validate, and apply a new questionnaire tailored specifically to measure the transferability within a multiple device system. The System Transferability Questionnaire (STQ) is obtained after validation with 15 question items. In a software usability study, the STQ demonstrated excellent internal reliability and validity. Results show that the STQ is effective in capturing four factors regarding transferability, which are transfer experience (TE), overall experience (OE), consistency perception (CP) and functionality perception (FP). Validation results show good convergent, discriminant, criterion and nomonlogical validity. Study two adopts a systematic tool to consolidate usability constructs into a total usability score. The study utilizes principal component analysis (PCA) to determine the weight of the four usability components (satisfaction, transferability, effectiveness, and efficiency), which is used when obtaining the total usability score. Results show slightly different weights for the four components. This quantitative tool can be applied in different usability context in which multiple devices are involved. Usability specialists are encouraged to adjust the tool based on different usability scenarios. Study three investigates the impact of task complexity, user experience, and device order on the total system usability. Results show that the total usability score is not affected by task complexity, user experience or device order. However, lower physical task complexity leads to longer performance time and lower errors from the users. High experienced users have significantly lower errors made in tasks. The machine order also has divergent results. When the mini-lathe machine was used first, users had better transferability results but poorer performance outcomes as compared to when the drill press was used first.

Entwicklung und Test eines Prototypen nach den Maßstäben des Usage Centered Desings (nach Constantine und Lockwood). Der Prototyp beschäftigt sich mit der Organisation / Planung von Schulungen im Kontext geflüchteter Menschen in den Ländern Südsudan und Uganda und verfolgt dabei den mobile first Ansatz. Augenmerk wird auf die Gestalung einer benutzungsoptmierten Applikation in einem kulturell fremden Kontext gelegt.:I. Einleitung A. Krieg im Südsudan und dessen Auswirkungen B. #ASKnet 1. Ziel 2. Mitglieder und Organisation C. ASKtraining II. Usage-Centered Design A. User groups B. Interviews C. Role Modeling 1. User Role 2. Focal Roles 3. User Role Map D. Task Modeling 1. Personas 2. Scenarios 3. Conventional Use Cases 4. Essential Use Cases 5. Use Case Map 6. Focal Use Case E. Interface Contents and Navigation 1. Interaction Context 2. Tools and Materials 3. Context Navigation Map 4. Funktionsumfang und Prinzipien III. Visual Design A. Sketching B. Interaktiver Prototyp 1. Design 2. Prototyping 3. Icons IV. Tests und Evaluation A. Usability Test 1. Planung des Tests 2. Ausführung des Tests B. Evaluation V. Perspektive VI. Reflexion VII. Danksagung VIII.Literaturverzeichnis IX. Abbildungsverzeichnis X. Anhang A. Fragenkatalog Interviews - erste Runde B. Zusammenfassung Interviews - erste Runde C. Fragenkatalog Interviews - zweite Runde D. Services provided by Application E. Role Model F. Personas G. Scenarios H. Conventional Use Cases I. Essential Use Cases J. Use Case Map K. Interaction Context L. Tools and Materials M. Context Navigation Map N. Sketches O. Interaktiver Prototyp P. Usability Test - Vorbereitung Q. Usability Test - Aufgaben R. Usability Test - Proband:innen S. Usability Test - Evaluation: Tabelle T. Usability Test - Evaluation: Bericht

Interacting with user interfaces has becoming something that everyone of all ages is doing whether it be using smart devices like phones and tablets, ordering at fast-food restaurants, watching movies on a plane, etc. With people of all ages interacting with interfaces, designers need to consider what limitations and barriers come with different age groups. This thesis aims to improve how elderly users interact with accessibility features on iPhones. The initial user testing conducted with elderly users discovered that many users are comfortable with their iPhones interface but that they could potentially benefit from accessibility features but are hesitant to explore. These insights were utilized in redesigning the interface for accessibility options on iOS, with the goal of creating a more inviting and user-friendly feature for elderly users. Final user testing showed that elderly users benefited from efficient interactions and instruction guides to make and perceive accessibility changes more effectively. The aim of the redesign was to address the users worries including confusion, hesitancy, and insufficient feedback.

Spreadsheets are one of the most frequently used applications. They are used because they are easy to understand and values can be updated easily. However, many people try to use spreadsheets for problems beyond their intended scope and end up with errors and miscalculations. We present a new spreadsheet system which uses complex-values and equation code reuse to overcome the limitations of spreadsheets for complex problems. We also discuss the features necessary in order to make these enhancements useful and effective.

The purpose of this study was to create a web application that provided peer to peer rental solutions for students and while doing so maximize the usability of the application with regards to simplicity and online trust. An initial market survey was conducted, see appendix B, and the overall results were promising. The few survey takers that were hesitant towards the idea thought that using a rental solution would not be worth the while. Hence the research question focused on maximizing usability in regards to simplicity and online trust in order to make the e-shop an easy rental solution to use. The application was developed in three iterations and through the development process user tests were conducted and metrics regarding simplicity and perceived online trust were collected. The test conducted made use of the concurrent think aloud procedure, retrospective probing, surveying and time data used for calculating the effectiveness and efficiency of the test participants. The test results all improved throughout the development process and the application was perceived as both simple and trustworthy by test participants. By the end of the study, an application that could provide a peer to peer rental solution that was trusted by its users and was simple to use was realized. The study concluded that the evaluation methods used were good indicators of whether a web application is simple and trustworthy by identifying issues with the application as well as the improvements reflected in the test results. However they should have been applied on separate test occasions.

Technological advances in products and systems have brought emotional design or emotional engineering to the forefront of research. While several measures to assess emotional expression of products have been developed, the source of the emotion rating of a product or system was often unclear. The purpose of this dissertation is to conduct three studies to examine the causes of emotional ratings and to establish if product-specific emotion rating scales are useful for capturing accurate user evaluations. Three studies were conducted using citrus juicers. Juicers were chosen for several reasons: their wide variety of styles, one self-explanatory purpose (to make juice), and the fact that their benign nature is unlikely to harm participants. Study 1 isolated juicers that had unique emotion profiles to use in the Study 2. Participants rated 41 juicers with fourteen product-specific emotions. Participants predominantly used "five" of the fourteen emotions in their juicer ratings. Ten juicers with the highest rating consensus, within these five emotions, were chosen for Study 2. Study 2 determined that anthropomorphic tendencies are predictive of emotional ratings. Extreme Anthropomorphism from the Anthropomorphic Tendency Scale (ATS) was used to test individual differences (Sims et al. 2005;Chin et al., 2005). Individuals with low anthropomorphic tendencies were more critical of the products. Sex differences also were analyzed, and significant interactions were found. Women exhibited different preferences for juicers than me. First impression ratings from Study 1 were validated by first impression ratings from Study 2. Finally, Study 3 measured the impact of product interaction on emotional ratings. Participants used seven juicers to make a minimum of four ounces of juice. Pre and post-interaction ratings were compared to determine the effect of interaction on the emotional appraisal of products. The results confirmed that interaction had an impact on affective ratings. As opposed to experienced users, novice users deviated in their pre-post appraisal, especially on aesthetically boring but highly usable products. Novice users based their entire initial appraisal on aesthetics, while experienced users were influenced by their past experience. Humans rely on past experience to recall likes or dislikes. The findings here suggest that aesthetic appraisal of products (or other environments) will remain influenced by past exposure/experience with those or similar products. Thus, only true novices can remain unbiased by past experience for aesthetic appraisal and capture a true 'first impression'. Also, past experience of users should be assessed when conducting research that relies on emotional appraisal of products. These findings may be especially useful in product development where new designs are based on a golden standard, competition, or go through several iterations of testing. The results may be used to guide human factors professionals to develop measures that more accurately capture affective ratings, and thus create more pleasurable products and systems.

We live in an age when consumers can now shop and browse the web using hand-held devices. This means that competitive companies need to have a website to represent their brand and to conduct business. E-commerce sites need to pay special attention to the usability of their sites, since it has such an impact on how potential costumers view their brand. Jakob Nielsen defines usability as a "quality attribute that assesses how easy user interfaces are to use"; he separates usability into five quality components: learnability, efficiency, memorability, errors and satisfaction. The current standard for testing usability involves having a number of users physically use a site in order to determine where they have trouble. This kind of usability testing can be time consuming and costly. In order to mitigate some of these costs, many tools are being developed to help automate the process. However, many automated tools evaluate only one of the five components, or simply look for errors. In an attempt to increase the reliability and scope of such testing, this paper investigates the effectiveness of automated usability evaluators and proposes methods for future researchers to test them. Specifically, this paper details an experiment performed to test the some freely available usability evaluators against more traditional usability evaluations. The experiment attempts to determine whether automatic usability evaluations might be used as a cheaper alternative to more traditional usability evaluations.