Effective methods for information access are of the greatest importance for our modern lives – particularly with respect to handheld devices. Personalisation is one such method which models a user’s characteristics to deliver content more focused to the user’s needs. The emerging area of sophisticated mobile computing devices has started to inspire new forms of personalised systems that include aspects of the person’s contextual environment. This thesis seeks to understand the role of personalisation and context, to evaluate the effectiveness of context for content personalisation and to investigate the event and map content domain for mobile usage. The work presented in this thesis has three parts: The first part is a user experiment on context that investigated the contextual attributes of time, location and interest, with respect to participants’ perception of their usefulness. Results show highly dynamic and interconnected effects of context on participants’ usefulness ratings. In the second part, these results were applied to create a predictive model of context that was related to attribution theory and then combined with an information retrieval score to create a weighted personalisation model. In the third part of this work, the personalisation model was applied in a mobile experiment. Participants solved situational search tasks using a (i) non-personalized and a (ii) personalized mobile information system, and rating entertainment events based on usefulness. Results showed that the personalised system delivered about 20% more useful content to the mobile user than the non-personalised system, with some indication for reduced search effort in terms of time and the amount of queries per task. The work presented provides evidence for the promising potential of context to facilitate personalised information delivery to users of mobile devices. Overall, it serves as an example of an investigation into the effectiveness of context from multiple angles and provides a potential link to some of the aspects of psychology as a potential source for a deeper understanding of contextual processes in humans.

Multi-sensory feedback can potentially improve user experience and performance in virtual environments. As it is complicated to study the effect of multi-sensory feedback as a single factor, we created a design space with these diverse cues, categorizing them into an appropriate granularity based on their origin and use cases. To examine the effects of tactile cues during non-fatiguing walking in immersive virtual environments, we selected certain tactile cues from the design space, movement wind, directional wind and footstep vibration, and another cue, footstep sounds, and investigated their influence and interaction with each other in more detail. We developed a virtual reality system with non-fatiguing walking interaction and low-latency, multi-sensory feedback, and then used it to conduct two successive experiments measuring user experience and performance through a triangle-completion task. We noticed some effects due to the addition of footstep vibration on task performance, and saw significant improvement due to the added tactile cues in reported user experience.

A high level of programming knowledge is needed in order to script a video game. This prevents video game design from being accessible to non-programmers. ScriptEase is a tool that was designed to solve this problem. While ScriptEase has been shown to be accessible to 10th grade English students there remains areas for further simplication. This thesis focuses on changing the way authors set options within ScriptEase by introducing a new technique called Describers. Describers allow authors to adapt plain English sentences to provide a description of each option. A user study was conducted that compared Describers against the original technique of using denitions. The participants were able to complete signicantly more statements and showed a preference for the Describer. Simplications such as the Describers will lower the entrance bar for an author. The underlying structure of the Describer can be used to simplify creating conditional statements.

Online tasks that involve information gathering, those ranging from academic research to vacation planning, often present challenges to users such as information management, clutter and information overload. Studies have shown that users who return to online tasks after an absence have difficulty remembering why particular websites they had saved were useful. This work presents "Webscraps", an innovative web browser extension for Mozilla Firefox, designed to improve information gathering on the Web. Participants in a 30-person user study, significantly preferred Webscraps over webpage "thumbnails" for information gathering tasks that involved comparing information from different websites and remembering important text. / Dr. Keselj was the external to my supervision.

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Information Retrieval, as a field, has long subscribed to an orthodox evaluation approach known as the Cranfield paradigm. This approach and the assumptions that underpin it have been essential to building the traditional search engine infrastructure that drives today’s modern information economy. In order to build the information economy of tomorrow, however, we must be prepared to reexamine these assumptions and create new, more sophisticated standards of evaluation to match the more complex information retrieval systems on the horizon. In this thesis, we begin this introspective process and launch our own evaluation method for one of these complex IR systems, entity-relationship recommenders. We will begin building a new user model adapted to the needs of a different user experience. To support these endeavors, we will also conduct a study with a mockup of our complex system to collect real behavior data and evaluation results. By the end of this work, we shall present a new evaluative approach for one kind of entity-relationship system and point the way for other advanced systems to come.

This research studied egocentric depth perception in an augmented reality (AR) environment. Specifically, it involved measuring depth perception in the near visual field by using quantitative methods to measure the depth relationships between real and virtual objects. This research involved two goals; first, engineering a depth perception measurement apparatus and related calibration andmeasuring techniques for collecting depth judgments, and second, testing its effectiveness by conducting an experiment. The experiment compared two complimentary depth judgment protocols: perceptual matching (a closed-loop task) and blind reaching (an open-loop task). It also studied the effect of a highly salient occluding surface; this surface appeared behind, coincident with, and in front of virtual objects. Finally, the experiment studied the relationship between dark vergence and depth perception.

We present the results from a user study looking at the ability of observers to mentally integrate wind direction and magnitude over a vector field. The data set chosen for the study is an MM5 (PSU/NCAR Mesoscale Model) simulation of Hurricane Lili over the Gulf of Mexico as it approaches the southeastern United States. Nine observers participated in the study. This study investigates the effect of layering on the observer's ability to detrmine the magnitude and direction of a vector field. We found a tendency for observers to underestimate the magnitude of the vectors and a counter-clockwise bias when determining the average direction of a vector field. We completed an additional study with two observers to try to uncover the source of the counter-clockwise bias. These results have direct implications to atmospheric scientists, but may also be able to be applied to other fields that use 2D vector fields.

Passwords continue to dominate the authentication landscape in spite of numerous proposals to replace them. Even though usability is a key factor in replacing passwords, very few alternatives have been subjected to formal usability studies and even fewer have been analyzed using a standard metric. We report the results of four within-subjects usability studies for seven web authentication systems. These systems span federated, smartphone, paper tokens, and email-based approaches. Our results indicate that participants prefer single sign-on systems. We utilize the Systems Usability Scale (SUS) as a standard metric for empirical analysis and find that it produces reliable, replicable results. SUS proves to be an accurate measure of baseline usability and we recommend that going forward all new authentication proposals be required to meet a minimum SUS score before being accepted by the security community. Our usability studies also gather insightful information from participants' qualitative responses: we find that transparency increases usability but also leads to confusion and a lack of trust, participants prefer single sign-on but wish to augment it with site-specific low-entropy passwords, and participants are intrigued by biometrics and phone-based authentication.

We present an exploration that surveys the strengths and weaknesses of various 3D spatial interaction techniques, in the context of directly manipulating an Unmanned Aerial Vehicle (UAV). Particularly, a study of touch- and device- free interfaces in this domain is provided. 3D spatial interaction can be achieved using hand-held motion control devices such as the Nintendo Wiimote, but computer vision systems offer a different and perhaps more natural method. In general, 3D user interfaces (3DUI) enable a user to interact with a system on a more robust and potentially more meaningful scale. We discuss the design and development of various 3D interaction techniques using commercially available computer vision systems, and provide an exploration of the effects that these techniques have on an overall user experience in the UAV domain. Specific qualities of the user experience are targeted, including the perceived intuition, ease of use, comfort, and others. We present a complete user study for upper-body gestures, and preliminary reactions towards 3DUI using hand-and-finger gestures are also discussed. The results provide evidence that supports the use of 3DUI in this domain, as well as the use of certain styles of techniques over others.