Personal Digital Assistants (PDAs) have recently become a popular component in mobile robots. This compact processing device with its touch screen, variety of built-in features, wireless technologies and affordability can perform various roles within a robotic system. Applications include low-cost prototype development, rapid prototyping, low-cost humanoid robots, robot control, robot vision systems, algorithm development, human-robot interaction, mobile user interfaces as well as wireless robot communication schemes. Limits on processing power, memory, battery life and screen size impact the usefulness of a PDA in some applications. In addition various implementation strategies exist, each with its own strengths and weaknesses. No comparison of the advantages and disadvantages of the different strategies and resulting architectures exist. This makes it difficult for designers to decide on the best use of a PDA within their mobile robot system. This dissertation examines and compares the available mobile robot architectures. A thorough literature study identifies robot projects using a PDA and examines how the designs incorporate a PDA and what purpose it fulfils within the system it forms part of. The dissertation categorises the architectures according to the role of the PDA within the robot system. The hypothesis is made that using a distributed control system architecture makes optimal use of the rich feature set gained from including a PDA in a robot system’s design and simultaneously overcomes the device’s inherent shortcomings. This architecture is developed into a novel distributed intelligence framework that is supported by a hybrid communications architecture, using two wireless connection schemes. A prototype implementation illustrates the framework and communications architecture in action. Various performance measurements are taken in a test scenario for an office robot. The results indicate that the proposed framework does deliver performance gains and is a viable alternative for future projects in this area.

New innovative products are being designed while the user interface of existing products is constantly being revamped to give them a new look. All this is an effort to bring a satisfactory interacting experience for the user. However, in most cases users do not feel that they experience that benefit. The introduction of a new product, or the enhancement of the functionality and user interface of an existing product, often faces criticism and brings resistance to the acceptance and usage of the product by the users. Therefore, the change in user interface or introduction of new products does not only affect the business processes but also the lifestyles of the users, as well as their overall user experience. One of the most important components for the success of any product is a positive user experience. User experience refers to the subjective feeling of the user that results from their interaction or intention to interact with a product in order to perform a specific task in a specific environment. When the user interface and functionality of a product match the expectations of the users and make the users effective and efficient, feel safe and attain some level of self-worth from using or possessing the product, their interaction with the product becomes more satisfactory. User experience practitioners are in agreement that a change to the user interface influences the user experience of the people when interacting with the product; hence it affects change in the user experience of the people. A vast body of literature exists on the methods for evaluating user experience as well as on the principles that are aimed at guiding the design of products for a positive user experience. However, there is a lack of a means to manage this change in user experience that results from the changes in the features of the user interface or the product functionalities. This inadequacy opens up the potential for integrating change management principles in order to manage user experience. However, existing change management principles do not address the user experience aspects when managing change. Following the above premise, this study focused on the development of a model for managing user experience: the User Experience Management Model (UXM2). The UXM2 infers its components from the disciplines of user experience and change management. Its uniqueness is seated in its people-centred approach that aims to effect a free-will change in the individuals towards a long-term positive user experience. The proposed model further aims to promote the voluntary acceptance of a product, which is contrary to the mandatory change that is guided by the policies of the organization, as discussed in the study. The UXM2 was developed from a thorough argumentation of literature on user experience and change management. The components that were required for development of the model were identified from literature, and were evaluated for their relevance by means of academic publications in subject domain international conferences. The academic publications underwent double-blind peer review with subject domain experts. The model was evaluated for its relevance and potential applicability through interviews and discussions with subject domain experts. The subject domain experts consist of user experience practitioners and academic professionals in the domain of HCI. The subject domain experts also evaluated the model by means of an evaluation tool comprising of a Likert scale rating of the proposed components and related activities for managing user experience. The target users of the UXM2 are user experience practitioners and product developers who aim to promote a sustainable long-term positive user experience for the people interacting with their products. The UXM2 is aimed at being used for the design of products that are meant for institutional use, personal use, mandatory use and optional use. It is believed that adoption of the UXM2 will promote acceptance of the product by users, with an associated sustainable positive long-term user experience.

As user interfaces become more powerful and easier to use they are often harder to design and implement. This has caused a great demand for interface tools. While existing tools ease interface creation, they typically do not provide mechanisms to simplify application development and are too low-level. Furthermore, existing tools do not provide effective mechanisms to port interactive applications across user interfaces. While some tools provide limited mechanisms to port applications across user interfaces which belong to the same class (e.g., the class of all standard graphical direct-manipulation user interfaces), very few can provide the ability to port applications across different interface classes (e.g., command-line, hypermedia, speech recognition and voice synthesis, virtual reality, etc.). With my approach, the programmer uses an abstract model to describe the structure of the application including the information that the application must exchange with the user, rather than describing a user interface which realizes these characteristics. By specifying application semantics at a very high level of abstraction it is possible to obtain a much greater separation between the application and the user interface. Consequently, the resulting applications can be ported not only across user interfaces which belong to a common interface class, but across interfaces which belong to distinct classes. This can be realized through simple recompilation - source code does not have to be modified. NAAG (Not Another Application Generator), a tool which embodies these ideas, enables programmers to create interactive applications with minimal effort. An application is modelled as a set of operations which manipulate objects belonging to user-defined object classes. The input to NAAG is a source program which describes classes, operations and their inputs and outputs, and the organization of operations within the application. Classes and operations are implemented as data structures and functions in a conventional programming language such as C. This model simplifies not only the specification and generation of the user interface, but the design and implementation of the underlying application. NAAG utilizes existing technology such as macro-preprocessors, compilers, make programs, and low-level interface tools, to reduce the programming task. An application that is modified by adding, removing, or reorganizing artifacts (classes, operations, and menus), can be regenerated with a single command. Traditionally, software maintenance has been a very difficult task as well. Due to the use of a simple abstract model, NAAG applications are also easier to maintain. Furthermore, this approach encourages software reuse: applications consisting of arbitrary collections of original and pre-existing artifacts can be composed easily; functions which implement abstract operations are independent of both, user interface aspects, and the context in which they are employed. Application development is further simplified in the following ways: the programmer describes the semantics of the user interface - a conventional explicit specification is not required; output primitives are defined in an interface-independent manner; many programming tasks such as resource management, event processing, and communication, are either handled directly by the tool or else simplified greatly for the programmer. NAAG is currently used by the members of the Laboratory for Computational Vision at the University of British Columbia to maintain a sophisticated image processing system. / Science, Faculty of / Computer Science, Department of / Graduate

Although many selection techniques have been proposed and developed over the years, selection by pointing is perhaps the most popular approach for selection. In 3D interfaces, the laser-pointer metaphor is commonly used, since users only have to point to their target from a distance. However, the task of selecting objects that have a small visible area or that are in highly cluttered environments is hard when using pointing techniques. With both indirect and direct pointing techniques in 3D interfaces, smaller targets require higher levels of pointing precision from the user. In addition, issues such as target occlusion as well as hand and tracker jitter negatively affect user performance. Therefore, requiring the user to perform selection in a single precise step may result in users spending more time to select targets so that they can be more accurate (effect known as the speed-accuracy trade-off). We describe an approach to address this issue, called Progressive Refinement. Instead of performing a single precise selection, users gradually reduce the set of selectable objects to reduce the required precision of the task. This approach, however, has an inherent trade-off when compared to immediate selection techniques. Progressive refinement requires a gradual process of selection, often using multiple steps, although each step can be fast, accurate, and nearly effortless. Immediate techniques, on the other hand, involve a single-step selection that requires effort and may be slower and more error-prone. Therefore, the goal of this work was to explore this trade-off. The research includes the design and evaluation of progressive refinement techniques for 3D interfaces, using both pointing- and gesture-based interfaces for single-object selection and volume selection. Our technique designs and other existing selection techniques that can be classified as progressive refinement were used to create a design space. We designed eight progressive refinement techniques and compared them to the most commonly used techniques (for a baseline comparison) and to other state-of-the-art selection techniques in a total of four empirical studies. Based on the results of the studies, we developed a set of design guidelines that will help other researchers design and use progressive refinement techniques. / Ph. D.

It is often assumed that more realism is always desirable. In particular, many techniques for locomotion in Virtual Reality (VR) attempt to approximate real-world walking. However, it is not yet fully understood how the design of more realistic locomotion techniques influences effectiveness and user experience. In the previous VR studies, the effects of interaction fidelity have been coarse-grained, considering interaction fidelity as a single construct. We argue that interaction fidelity consists of various independent components, and each component can have a different effect on the effectiveness of the interface. Moreover, the designer's intent can influence the effectiveness of an interface and needs to be considered in the design. Semi-natural locomotion interfaces can be difficult to use at first, due to a lack of interaction fidelity, and effective training would help users understand the forces they were feeling and better control their movements. Another method to improve locomotion interaction is to develop a more effective interface or improve the existing techniques. A detailed taxonomy of walking-based locomotion techniques would be beneficial to better understand, analyze, and design walking techniques for VR. We conducted four user studies and performed a meta-analysis on the literature to have a more in-depth understanding of the effects of interaction fidelity on effectiveness. We found that for the measures dependent on proprioceptive sensory information, such as orientation estimation, cognitive load, and sense of presence, the level of effectiveness increases with increasing levels of interaction fidelity. Other measures which depend more on the ease of learning and ease of use, such as completion time, movement accuracy, and subjective evaluation, form a u-shape uncanny valley. For such measures, moderate-fidelity interfaces are often outperformed by low- and high-fidelity interfaces. In our third user study, we further investigated the effects of components of interaction fidelity, biomechanics and transfer function, as well as designers' intent. We learned that the biomechanics of walking are more sensitive to changes and that the effects of these changes were mostly negative for hyper-natural techniques. Changes in the transfer function component were easier for the user to learn and to adapt to. Suitable transfer functions were able to improve some locomotion features but at the cost of accuracy. To improve the level of effectiveness in moderate-fidelity locomotion interfaces we employed an effective training method. We learned that providing a visual cue during the acclimation phase can help users better understand their walking in moderate-fidelity interfaces and improve their effectiveness. To develop a design space and classification of locomotion techniques, we designed a taxonomy for walking- based locomotion techniques. With this taxonomy, we extract and discuss various characteristics of locomotion interaction. Researchers can create novel locomotion techniques by making choices from the components of this taxonomy, they can analyze and improve existing techniques, or perform experiments to evaluate locomotion techniques in detail using the presented organization. As an example of using this taxonomy, we developed a novel locomotion interface by choosing a new combination of characteristics from the taxonomy. / Ph. D.

Thesis (Masters) -- University of Canberra, 2008. / Includes bibliography (p. 130-135) Also available online.

With the rise of powerful mobile devices and the broad availability of computing power, Automatic Speech Recognition is becoming ubiquitous. A flawless ASR system is still far from existence. Because of this, interactive applications that make use of ASR technology not always recognize speech perfectly, when not, the user must be engaged to repair the transcriptions. We explore a rational user interface that uses of machine learning models to make its best effort in presenting the best repair strategy available to reduce the time in spent the interaction between the user and the system as much as possible. A study is conducted to determine how different candidate policies perform and results are analyzed. After the analysis, the methodology is generalized in terms of a decision theoretical framework that can be used to evaluate the performance of other rational user interfaces that try to optimize an expected cost or utility.

Thesis (Ph.D.)--University of Wollongong, 2004. / Typescript. This thesis is subject to a 2 year embargo (16/09/2004 to 16/09/2006) and may only be viewed and copied with the permission of the author. For further information please Contact the Archivist. Includes bibliographical references: p. 360-374.

Thesis (PhD) - Swinburne University of Technology, 2006. / [Submitted for the degree of Doctor of Philosophy, Swinburne University of Technology - 2006]. Typescript. Includes bibliographical references (p. 218-231).

published_or_final_version / abstract / Mechanical Engineering / Doctoral / Doctor of Philosophy