No description available.

No description available.

Designing innovative computer systems is no longer simply a technical issue. There is now a growing awareness that a grounded understanding of the social and organisational context into which these systems are to be deployed, until recently overlooked, may be critical, particularly in the early phases of design. It is in these stages, known as requirements elicitation, capture or analysis, or more generally Requirements Engineering, that researchers have begun to acknowledge both social and technical concerns in the requirements for systems. This thesis aims to mediate between a detailed appreciation of the social organisation of the workplace and the technical structure of information technology. In order to do this, we explore the relevance of recent developments in the social sciences, principally ethnomethodology and interaction analysis, for providing an alternative analytic orientation for requirements capture. In particular, we outline the principal characteristics of an approach that takes into account the details of the moment-to-moment production of work activities and communicative practices. It is argued that attendance to such interactional features will improve requirements practice, and hence will ultimately lead to more sensitive designs for supporting collaborative work. To illustrate this approach, we take as an example the development of particular technologies for a complex work setting - financial trading rooms. Results of the analysis are then used to discuss requirements for systems to support trading. In particular, we consider how issues emerging from this analysis, developed from an ethnomethodological orientation, could inform requirements analysis. In this regard, we investigate approaches to modelling interactional resources, including the use of formal notations developed for sequential and communicating processes, and provide requirements analysts with sensitivities by which to consider naturalistic settings. This forms the basis for mutually dependent investigations: on the system design side, drawing on the model to allow consideration of conflicts introduced by technological choices; and on the social science side, providing an agenda for renewed investigation into the domain. We conclude by discussing the pre-requisites necessary so that approaches in this thesis could be integrated within the software development process.

Not available / text

Mobile phones are increasingly being equipped with a wide range of sensors which enable a variety of interaction techniques. Sensor-based interaction techniques are particularly promising for domains such as map-based applications, where the user is required to interact with a large information space on the small screen of a mobile phone. Traditional interaction techniques have several shortcomings for interacting with mobile map-based applications. Keypad interaction offers limited control over panning speed and direction. Touch-screen interaction is often a two-handed form of interaction and results in the display being occluded during interaction. Sensor-based interaction provides the potential to address many of these shortcomings, but currently suffers from several limitations. The aim of this research was to propose enhancements to address the shortcomings of sensor-based interaction, with a particular focus on tilt interaction. A comparative study between tilt and keypad interaction was conducted using a prototype mobile map-based application. This user study was conducted in order to identify shortcomings and opportunities for improving tilt interaction techniques in this domain. Several shortcomings, including controllability, mental demand and practicality concerns were highlighted. Several enhanced tilt interaction techniques were proposed to address these shortcomings. These techniques were the use of visual and vibrotactile feedback, attractors, gesture zooming, sensitivity adaptation and dwell-time selection. The results of a comparative user study showed that the proposed techniques achieved several improvements in terms of the problem areas identified earlier. The use of sensor fusion for tilt interaction was compared to an accelerometer-only approach which has been widely applied in existing research. This evaluation was motivated by advances in mobile sensor technology which have led to the widespread adoption of digital compass and gyroscope sensors. The results of a comparative user study between sensor fusion and accelerometer-only implementations of tilt interaction showed several advantages for the use of sensor fusion, particularly in a walking context of use. Modifications to sensitivity adaptation and the use of tilt to perform zooming were also investigated. These modifications were designed to address controllability shortcomings identified in earlier experimental work. The results of a comparison between tilt zooming and Summary gesture zooming indicated that tilt zooming offered better results, both in terms of performance and subjective user ratings. Modifications to the original sensitivity adaptation algorithm were only partly successful. Greater accuracy improvements were achieved for walking tasks, but the use of dynamic dampening factors was found to be confusing. The results of this research were used to propose a framework for mobile tilt interaction. This framework provides an overview of the tilt interaction process and highlights how the enhanced techniques proposed in this research can be integrated into the design of tilt interaction techniques. The framework also proposes an application architecture which was implemented as an Application Programming Interface (API). This API was successfully used in the development of two prototype mobile applications incorporating tilt interaction.

A user-centered approach to interactive system development requires a way to represent the behavior of a user interacting with an interface. While a number of behavioral representation techniques exist, not all provide the capabilities necessary to support the interaction development process. The original goal of this research was to modify and extend the User Action Notation (UAN), a user- and task-centered behavioral representation technique. In order to facilitate and evaluate the improvement in the UAN, we developed and evaluated a taxonomic model of behavioral representation techniques. The development and evaluation of our model followed the epistemological cycle of observation, theorization, and evaluation. The model provides a framework for discussing, analyzing, extending, and comparing existing behavioral representation techniques, as well as being a springboard for developing and evaluating new techniques. / Ph. D.

The user interface development process occurs in a behavioral domain and in a constructional domain. The development process in the behavioral domain focuses on the "look and feel" of the user interface and its behavior in response to user actions. The development process in the constructional domain focuses on developing software to implement the user interface. Although one may attempt to design a user interface from a constructional view, it is important to concentrate design efforts in the behavioral domain to improve software usability. User Action Notation (UAN) is a useful technique for representing user interaction designs in the behavioral domain. Primary abstractions in UAN-expressed designs are user tasks. Information about interface objects is encapsulated in user task descriptions and scenarios. Primary abstractions in a GUI such as Motif™ are interface objects. Motif implements objects' behavior and appearance using system functions that are encapsulated within pre-defined object classes. Therefore, user interaction developers and software developers must communicate well to translate UAN-expressed interaction designs into Motif-based software designs. Translation is not trivial since it is a translation between two significantly different domains. This thesis contributes to understanding of the user interface development process by developing a foundation to assist translation of user interaction designs into Motif-based software designs. This thesis develops the foundation as follows: 1. Adapt UAN for use with Motif. 2. Summarize Motif concepts about objects and object relationships. 3. Develop new approaches for discussing objects and object relationships. 4. Develop a partial translation guide containing VAN descriptions of selected Motif abstractions. / Master of Science

see PDF

Thesis (M. Tech.: Information Technology)-Dept. of Information Technology, Durban Institute of Technology, 2005 xiv, 170, [20] leaves / This study examines the efficiency, ease of use and ease of understanding of user interface designs implemented in current e-commerce websites. Four South African based e-commerce websites formed the test cases of this study. Selection of the test cases was based on the results and conclusions of previous surveys conducted by an independent research institution. The outcome of that survey identified the most popular e-commerce websites among South African internet users.

Behavioral synthesis is the process of compiling an Electronic System Level (ESL) design to a register-transfer level (RTL) implementation. ESL specifications define the design functionality at a high level of abstraction (e.g., with C/C++ or SystemC), and thus provide a promising approach to address the exacting demands to develop feature-rich, optimized, and complex hardware systems within aggressive time-to-market schedules. Behavioral synthesis entails application of complex and error-prone transformations during the compilation process. Therefore, the adoption of behavioral synthesis highly depends on our ability to ensure that the synthesized RTL conforms to the ESL description. This dissertation provides an end-to-end scalable equivalence checking support for behavioral synthesis. The major challenge of this research is to bridge the huge semantic gap between the ESL and RTL descriptions, which makes the direct comparison of designs in ESL and RTL difficult. Moreover, a large number and a wide variety of aggressive transformations from front-end to back-end require an end-to-end scalable checking framework. This dissertation provides an end-to-end scalable equivalence checking support for behavioral synthesis. The major challenge of this research is to bridge the huge semantic gap between the ESL and RTL descriptions, which makes the direct comparison of designs in ESL and RTL difficult. Moreover, a large number and a wide variety of aggressive transformations from front-end to back-end require an end-to-end scalable checking framework. A behavioral synthesis flow can be divided into three major phases, including 1) front-end : compiler transformations, 2) scheduling: assigning each operation a clock cycle and satisfying the user-specified constraints, and 3) back-end : local optimizations and RTL generation. In our end-to-end and incremental equivalence checking framework, we check each of the three phases one by one. Firstly, we check the front-end that consists of a sequence of compiler transformations by decomposing it into a series of checks, one for each transformation applied. We symbolically explore paths in the input and output programs of each transformation, and check whether the input and output programs have the same observable behavior under the same path condition. Secondly, we validate the scheduling transformation by checking the preservation of control and data dependencies, and the preservation of I/O timing in the user-specified scheduling mode. Thirdly, we symbolically simulate the scheduled design and the generated RTL cycle by cycle, and check the equivalence of each mapped variables. We also develop several key optimizations to make our back-end checker scale to real industrial-strength designs. In addition to the equivalence checking framework, we also present an approach to detecting deadlocks introduced by parallelization of RTL blocks that are connected by synthesized interfaces with handshaking protocols. To demonstrate the efficiency and scalability of our framework, we evaluated it on transformations applied by a behavioral synthesis tool to designs from the C-based CHStone and SystemC-based S2CBench benchmarks. Based on the evaluation results, our front-end checker can efficiently validate more than 75 percent of the total of 1008 compiler transformations applied to designs from the CHStone benchmark, taking an average time of 1.5 seconds per transformation. Our scheduling checker can validate control-data dependencies and I/O timing of all designs from S2CBench benchmark. Our back-end checker can handle designs with more than 32K lines of synthesized RTL from the CHStone benchmark, which demonstrates the scalability of the checker. Furthermore, our checker found several bugs in a commercial tool, underlining both the importance of formal equivalence checking and the effectiveness of our approach.