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In the first chapter, the author explains his interest in computer-based information systems combined with their interactions with and use by members of the professions, as an on-going research focus and topic. After basic definitions, the discussion moves to the professions that are considered in the thesis and the organisational contexts in which their interactions with information systems occur. Finally, the chapter considers (1) the relevance of dissemination of research results as an integral and essential part of the research process and (2) the author's value framework, within which the studies described in the thesis are presented. The following chapter contains a review of research approaches employed in information systems and software engineering research. These approaches are examined to indicate how and where they have been used in the studies presented in the author's published papers reprinted in chapters three to nine. Because of the predominance of the action research perspective taken by the author, the rationale and results that can be achieved from the action research approach are specifically examined. Finally, chapter two considers the advantages of problem-driven research and the need for a diverse range of research approaches in information systems research. The following seven chapters are reprinted copies of published papers, four from journals and three from conferences. Chapter 3 describes a management problem related to ancillary works of the Thames Barrier; chapter 4 describes optimisation techniques and minimum cost design as used by engineers; chapter 5 describes an accountant's management information system; chapter 6 describes a knowledge-based system related to the selection of pacemakers for a cardiologist; chapter 7 relates to education of engineers in mid-career; and chapters 8 and 9 relate to the education of medical students and doctors in mid-career. The final chapter, chapter 10, reflects on the work described in the earlier chapters; and on factors which might have affected the outcomes of the research. These factors include (1) the role of the author who for periods operated as a consultant-researcher, and (2) the fact that the studies were undertaken in organisations and situations in which a managerialist climate existed. This is followed by research conclusions and implications for future research.

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This thesis presents a model for programming support for synchronous, distributed CSCW (Computer Supported Co-operative Work). Synchronous, distributed CSCW aims to allow groups of people separated, by distance to work together in real time as if they were at the same location. The model proposed in the thesis allows an application program to be constructed using user interface components known as “shared widgets”. A shared widget displays underlying application data on multiple screens and processes input from multiple users distributed over a network. The distribution of data to and from the users and the underlying network communication is hidden from the application program within the shared widget. The model describes a shared widget as comprising a single “Artefact” and a number of “Views.” The Artefact contains the underlying data and the actions that can be performed on it. A View is the presentation of the Artefact on a user's screen. Shared widgets contain a View for each user in the group. Each user can provide input to the Artefact via their own View, and any change made to the Artefact is reflected synchronously in all the Views. The Artefact can also impose a floor control policy to restrict input to a particular user or group of users, by checking each input event against a known floor control value. The model differs from previous approaches to programming support for CSCW in that the distributed nature of the users is hidden from the application programmer within the shared widgets. As a result, the application programmer does not have to be concerned with the processing of input events or the distribution of output to multiple users. The hiding of these implementation details within the shared widgets allows the CSCW application to be constructed in a similar way to a single-user application. An implementation of the shared widget model, using X Windows, is also described in the thesis. Experimental results and observations are given and used to suggest future directions for further research.

This thesis describes a methodology for the requirements analysis of critical real-time systems. The methodology is based on formal methods, and provides a systematic way in which requirements can be analysed and specifications produced. The proposed methodology consists of a framework with distinct phases of analysis, a set oftechniques appropriate for the issues to be analysed at each phase of the framework, a hierarchical structure of the specifications obtained from the process of analysis, and techniques to perform quality assessment of the specifications. The phases of the framework, which are abstraction levels for the analysis of the requirements, follow directly from a general structure adopted for critical real-time systems. The intention is to define abstraction levels, or domains, in which the analysis of requirements can be performed in terms of specific properties of the system, thus reducing the inherent complexity of the analysis. Depending on the issues to be analysed in each domain, the choice of the appropriate formalism is determined by the set of features, related to that domain, that a formalism should possess. In this work, instead of proposing new formalisms we concentrate on identifying and enumerating those features that a formalism should have. The specifications produced at each phase of the framework are organised by means of a specification hierarchy, which facilitates our assessment of the quality of the requirements specifications, and their traceability. Such an assessment should be performed by qualitative and quantitative means in order to obtain high confidence (assurance) that the level of safety is acceptable. In order to exemplify the proposed methodology for the requirements analysis of critical real-time systems we discuss a case study based on a crossing of two rail tracks (in a model railway), which raises safety issues that are similar to those found at a traditional level crossing (i.e. rail-road).

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