Gaze Guidance, Task-Based Eye Movement Prediction, and Real-World Task Inference using Eye Tracking

The ability to predict and guide viewer attention has important applications in computer graphics, image understanding, object detection, visual search and training. Human eye movements provide insight into the cognitive processes involved in task performance and there has been extensive research on what factors guide viewer attention in a scene. It has been shown, for example, that saliency in the image, scene context, and task at hand play significant roles in guiding attention. This dissertation presents and discusses research on visual attention with specific focus on the use of subtle visual cues to guide viewer gaze and the development of algorithms to predict the distribution of gaze about a scene. Specific contributions of this work include: a framework for gaze guidance to enable problem solving and spatial learning, a novel algorithm for task-based eye movement prediction, and a system for real-world task inference using eye tracking. A gaze guidance approach is presented that combines eye tracking with subtle image-space modulations to guide viewer gaze about a scene. Several experiments were conducted using this approach to examine its impact on short-term spatial information recall, task sequencing, training, and password recollection. A model of human visual attention prediction that uses saliency maps, scene feature maps and task-based eye movements to predict regions of interest was also developed. This model was used to automatically select target regions for active gaze guidance to improve search task performance. Finally, we develop a framework for inferring real-world tasks using image features and eye movement data. Overall, this dissertation naturally leads to an overarching framework, that combines all three contributions to provide a continuous feedback system to improve performance on repeated visual search tasks. This research has important applications in data visualization, problem solving, training, and online education

Identifying the Strengths and Weaknesses of Over-the-Shoulder Attack Resistant Prototypical Graphical Authentication Schemes

Authentication verifies users’ identities to protect against costly attacks. Graphical authentication schemes utilize pictures as passcodes rather than strings of characters. Pictures have been found to be more memorable than the strings of characters used in alphanumeric passwords. However, graphical passcodes have been criticized for being susceptible to Over-the-Shoulder Attacks (OSA). To overcome this concern, many graphical schemes have been designed to be resistant to OSA. Security to this type of attack is accomplished by grouping targets among distractors, translating the selection of targets elsewhere, disguising targets, and using gaze-based input. Prototypical examples of graphical schemes that use these strategies to bolster security against OSAs were directly compared in within-subjects runoffs in studies 1 and 2. The first aim of this research was to discover the current usability limitations of graphical schemes. The data suggested that error rates are a common issue among graphical passcodes attempting to resist OSAs. Studies 3 and 4 investigated the memorability of graphical passcodes when users need to remember multiple passcodes or longer passcodes. Longer passcodes provide advantages to security by protecting against brute force attacks, and multiple passcodes need to be investigated as users need to authenticate for numerous accounts. It was found that participants have strong item retention for passcodes of up to eight images and for up to eight accounts. Also these studies leveraged context to facilitate memorability. Context slightly improved the memorability of graphical passcodes when participants needed to remember credentials for eight accounts. These studies take steps toward understanding the readiness of graphical schemes as an authentication option

The Lived Experience of Vicarious Trauma for Providers: A Narrative Phenomenoleogical Study

This research seeks to gain a greater understanding of the first-hand, lived experience of vicarious trauma for providers who have worked with individuals experiencing trauma. Through the application of phenomenological and participatory action methodologies, the experience of vicarious trauma is illuminated. Narrative exchanges between the co-researchers–the author and eleven providers–further explore the roles of the body and narrative process within this phenomenon. A conceptual evolution of vicarious trauma is presented, along with literature connecting the body and narrative within the trauma field. Data includes co-researcher’s recorded and transcribed interviews, vicarious trauma narratives, and written feedback. Embodied writing selections conducted by the author serve as an additional form of data, capturing the nuanced, embodied data within the narrative process. Using narrative analysis, the major verbal and non-verbal themes of vicarious trauma are identified for the co-researchers involved in this study. Findings offer directions for future research into the phenomenon of vicarious trauma, as well as future suggestions for the development and application of body-based and dance/movement therapy techniques to address the impacts of vicarious trauma for providers working with the trauma field

Integrating Visual Mnemonics and Input Feedback with Passphrases to Improve the Usability and Security of Digital Authentication

The need for both usable and secure authentication is more pronounced than ever before. Security researchers and professionals will need to have a deep understanding of human factors to address these issues. Due to their ubiquity, recoverability, and low barrier of entry, passwords remain the most common means of digital authentication. However, fundamental human nature dictates that it is exceedingly difficult for people to generate secure passwords on their own. System-generated random passwords can be secure but are often unusable, which is why most passwords are still created by humans. We developed a simple system for automatically generating mnemonic phrases and supporting mnemonic images for randomly generated passwords. We found that study participants remembered their passwords significantly better using our system than with existing systems. To combat shoulder surfing - looking at a user\u27s screen or keyboard as he or she enters sensitive input such as passwords - we developed an input masking technique that was demonstrated to minimize the threat of shoulder surfing attacks while improving the usability of password entry over existing methods. We extended this previous work to support longer passphrases with increased security and evaluated the effectiveness of our new system against traditional passphrases. We found that our system exhibited greater memorability, increased usability and overall rankings, and maintained or improved upon the security of the traditional passphrase systems. Adopting our passphrase system will lead to more usable and secure digital authentication

Parent Perceived Stress and Child Temperament: Qualities that Facilitate or Impede Child Developmental Outcomes

Effective parent-child relationships contribute to the development of well-adjusted children. Taxing personal and situational factors encumber a caregiver’s capacity for responsivity with his or her child. The purpose of the present study was to identify interpersonal factors that impact child outcomes in low socioeconomic status family populations. Data was collected in northeast Florida Head Start centers from 219 low income, at-risk caregivers and their children ages one and a half through almost five. Parents completed questionnaires on parent perceived stress, child temperament, and child developmental outcomes. Hierarchical regression was used to assess the influence of child temperament and parent perceived stress independently and interactively on child developmental outcomes. Although parent stress and negative child temperament significantly influenced child developmental outcomes, there was no significant interaction effect. Policies aimed at ameliorating negative child temperaments or subjective parent stress may serve families and improve child developmental outcomes. Researchers should investigate the potential moderating influence of parent sensitive responding on the relationship between parent stress and child developmental outcomes

Try To See It My Way: Patient Perspective Video Capture Debriefing in Simulation

Video capture of simulation provides observation from a wide-angle view. This study introduced a new technique, “patient-perspective” video capture, using a camera mounted into eyeglasses allowing learners to view their nonverbal and verbal communication through the patient’s eyes and to compare this to the wide-angle view. The participants (n = 29) were Nurse Practitioner students. The majority were female (93.2%), with a mean age of 36.8, SD = 12.31. The sample consisted of Millennials (65.6%), Generation Xers (13.8%), and Baby Boomers (20.7%). The average number of years of nursing practice was 9.89. Instruments measured demographics, five domains of patient-centered care (PCC), and participant’s comparison of wide-angle and patient-perspective video capture. Analysis revealed significant differences between age groups in post-video perceptions of PCC domains, Interest in Patient Agenda x2(2) = 7.183, p = 0.028, and Patient Involvement in Care x2(2) = 8.084, p = 0.018. Post hoc analysis for both domains indicated the significance was between Baby Boomers and Millennials (U = 16.500, z = -2.597, p = 0.009; U = 15.500, z = -2.653, p = 0.008, respectively). A significant difference was found between post-video perception of Patient Involvement in Care based on Years of Nursing Practice, x2(2) = 8.874, p = 0.012. Post hoc test indicated the significant difference was between nurses with 1 to 5 years and 6 to 10 years (U = 17.500, z = -2.441, p = 0.015), and nurses with 1 to 5 years of practice and 11 or more years (U = 15.500, z = -2.593, p = 0.010). Participants identified benefits of both video capture techniques but found patient-perspective video more insightful for provider communication. Patient-perspective video capture enhances the debriefing experience and the reflective process regarding patient-provider communication

Improving the Security of Mobile Devices Through Multi-Dimensional and Analog Authentication

Mobile devices are ubiquitous in today\u27s society, and the usage of these devices for secure tasks like corporate email, banking, and stock trading grows by the day. The first, and often only, defense against attackers who get physical access to the device is the lock screen: the authentication task required to gain access to the device. To date mobile devices have languished under insecure authentication scheme offerings like PINs, Pattern Unlock, and biometrics-- or slow offerings like alphanumeric passwords. This work addresses the design and creation of five proof-of-concept authentication schemes that seek to increase the security of mobile authentication without compromising memorability or usability. These proof-of-concept schemes demonstrate the concept of Multi-Dimensional Authentication, a method of using data from unrelated dimensions of information, and the concept of Analog Authentication, a method utilizing continuous rather than discrete information. Security analysis will show that these schemes can be designed to exceed the security strength of alphanumeric passwords, resist shoulder-surfing in all but the worst-case scenarios, and offer significantly fewer hotspots than existing approaches. Usability analysis, including data collected from user studies in each of the five schemes, will show promising results for entry times, in some cases on-par with existing PIN or Pattern Unlock approaches, and comparable qualitative ratings with existing approaches. Memorability results will demonstrate that the psychological advantages utilized by these schemes can lead to real-world improvements in recall, in some instances leading to near-perfect recall after two weeks, significantly exceeding the recall rates of similarly secure alphanumeric passwords

Long-term English Learner: One Voice and Perspective of Schooling Experiences

The term Long-term English Learner (LTEL) is problematic. The terminology is used in schools and based upon the number of years that a student has been in US schools and has not met the criteria for reclassification as no longer requiring language support services, accommodations, or continued annual assessment, as required by the federal government for those with a second language learner designation. It can carry with it a connotation of a deficit for the student who remains an English learner beyond five years. This study centered around interviews and observations of a student who met the criteria for being identified as a LTEL in order to understand the impact student perceptions of the schools’ view of language and culture in learning. Transactional relationships in L1 and L2 use, as well as the students’ understanding of what aspects of culture to share within the school are discussed