This research represents an investigation into user acceptance of computer systems. It starts with the premise that existing systems do not fully meet user requirements, and are therefore rejected as 'difficult to use'. Various problems and influences affecting user acceptance are identified, and improvements are suggested. Although a broad range of factors affecting user acceptance are discussed, emphasis is given to the impact of actual computer software. Initially, both general and specific user interface software influences are examined, and it is shown how these needs can be met using new software technology. A new Intelligent Interface architecture model is presented, and comparisons are made to existing interface design approaches. Secondly, the role of empirical work within the field of Human Computer Interaction is highlighted. An investigation into the usability and user. acceptance of a large working library database system is described, and the results discussed. The role of Systems Analysis and Design and its effect upon user acceptance is also explored. It is argued that despite improvements in interface technology and related software engineering techniques, a software application is also a product of the Systems Analysis and Design process. Traditional Systems Design approaches are examined, and suitable improvements suggested based upon experience with emerging separable software architectures. Thirdly, the research proceeds to examine the potential of Quantitative User Modelling, and describes the implementation of an example object oriented Quantitative User Model. This is then evaluated in order to determine new knowledge, concerning the major issues surrounding the potential application of user modelling to interface design. Finally, attention is given to the concept of interface and application separation. An object oriented User Interface Management System is presented, and its implementation in the Smalltalk 80 programming language discussed. The proposed User Interface Management System utilises a new software architecture which provides explicit user interface separation, using the concept of a Pluggable View Controller. It also incorporates an integrated design Tool-set for Direct Manipulation interfaces. The proposed User Interface Management System and software architecture represents the major contribution of this project to the growing body of Human Computer Interaction research. In particular, the importance of explicit interface separation is established, and the proposed software architecture is critically evaluated to determine new knowledge concerning the requirements, constraints, and potential of proper user interface separation. The implementation of an object oriented Part Hierarchy mechanism is also presented. This mechanism is related to the proposed User Interface Management System, and is critically evaluated in order to add to the body of knowledge concerning object oriented systems.

No description available.

This dissertation is concerned with Computer Supported Cooperative Work (CSCW) and in particular with ways in which insights from ethnomethodology can be melded into the design of CSCW systems—a relationship that has been labelled technomethodology. The dissertation outlines a number of possible ways in which system design can learn from ethnomethodology and concentrates on one particular aspect—namely that CSCW should look closely at its foundational assumptions and, if necessary, re-specify any concepts which appear problematic in their formulation.

Improving communication between people and computer applications is a major concern of Human–Computer Interaction. One possible way of improving such communication is to capitalise on the way human beings use speech and gesture in a complementary manner, exploiting the redundancy of information between the input modes of a system. Redundant data input entered into a computer system through multiple modes, provides considerable scope for the resolution of error and ambiguity in the input message.

The purpose of the research described within this thesis is to provide information that can be used to improve the quality of programs and the productivity of the software industry. To fulfil this purpose, the thesis is concerned with the order in which software engineers construct solutions to software problems, the factors that influence the order in which software engineers construct solutions, and the effectiveness of constructing a solution in a particular order. Control strategies describe the order in which solutions are constructed. Four empirical studies investigating control strategies were undertaken to answer the concerns of the thesis. The aim of the first two studies was to observe the global control strategies employed by software engineers. The two studies collected verbal reports and keystroke behaviour of software engineers using Prolog and C. The results showed that software engineers used a combination of Top-Down control strategies to solve a software problem. A Children-First Top-Down control strategy was used during the initial stages of solving a complex sub-problem, while a Depth-First Top-Down control strategy was used to solve simple sub-problems. Occasionally software engineers diverged from a Top-Down control strategy. There were eight types of divergences (such as working pursuing pre-requisites) that frequently occurred within the context of six different activities (such as making alternations to a solution). The third study investigated the choice of local control strategies that supplement global control strategies. When software engineers were presented with a series of subproblems to complete, they chose to complete the four sub-problems in the order that they were presented. The software engineers did not choose to pursue the series of sub-problems in any alternative order, such as the order of Easiest-First, or AnalogiesFirst. The fourth study investigated the environmental factors that influence the software engineers' choice of global control strategies. The study also investigated whether software engineers using the Breadth-First control strategy produced better results than software engineers using alternative control strategies. Three different text editors were produced to determine under what circumstance software engineers would use the Breadth-First control strategy. The editors also recorded the behaviour of the software engineers. The software engineers would only use the Breadth-First control strategy when the text editor forced them to follow the Breadth-First control strategy. However, the performance of the software engineers was better when they were forced to use the Breadth-First control strategy than when they used their preferred control strategies.

No description available.

No description available.

With the very rapid increase in the availability of interactive computer systems emphasis has turned from algorithm and data structure design to man-machine interface design, in an attempt to produce interactive software that is acceptable to a user population with wide experience and ability levels. Considerable research has already been undertaken to obtain guidelines for man-machine dialogue design. However little has been done to integrate dialogue design methods and techniques into the traditional life cycle and methodologies of systems development, an area in which the author carried out earlier research. This thesis describes research undertaken to develop computer aids to assist with man-machine dialogue design, thus enabling dialogue representation techniques to be thoroughly proven. These techniques have been integrated with those of structured analysis to enable early specification of the dynamic aspects of a proposed interactive system, rather than their being left to the programming stage where there may be little user involvement. Additionally of interest is the ability of users to enter and modify dialogues using one of the developed computer aids, the Dialogue Prototyper. This system exhibits a novel approach to the provision of user adaptable interfaces.

No description available.

No description available.