The enormous computing power available today has resulted in the acceptance of information technology into a wide range of applications, the identification or creation of numerous problem areas, and the considerable tasks of finding problem solutions. Using computers for handling the current data manipulation tasks which characterise modern information processing requires considerably more sophisticated hardware and software technologies. Yet the development of more 'enhanced' packages frequently requires hundreds of man-years. Similarly, computer hardware design has become so complicated that only by using existing computers is it possible to develop newer machines. The common characteristic of such data manipulation tasks is that much larger amounts of information in evermore complex arrangements are being handled at greater speeds. Instead of being 'concrete' or 'black and white', issues at the higher levels of information processing can appear blurred - there may be much less precision because situations, perspectives and circumstances can vary. Most current packages focus on specific task areas, but the modern information processing environment actually requires a broader range of functions that cooperate in integrating and relating information handling activities in a manner far beyond that normally offered. It would seem that a fresh approach is required to examine all of the constituent problems. This report describes the research work carried out during such a consideration, and details the specification and development of a suggested method for enhancing information systems by specifying a multimedia information environment. This thesis develops a statement of the perceived problems, using extensive references to the current state of information system technologies. Examples are given of how some current systems approach the multiple tasks of processing and sharing data and applications. The discussion then moves to consider further what the underlying objectives of information handling - and a suitable integration architecture - should perhaps be, and shows how some current systems do not really meet these aims, although they incorporate certain of the essential fundamentals that contribute towards more enhanced information handling. The discussion provides the basis for the specification and construction of complete, integrated Information Environment applications. The environments are used to describe not only the jobs which the user wishes to carry out, but also the circumstances under which the job is being performed. The architecture uses a new geometric data structure to facilitate manipulation of the working data, relationships, and the environment description. The manipulation is carried out spatially, and this allows the user to work using a geometric representation of the data components, thus supporting the abstract nature of some information handling tasks.

The amount of semistructured data is growing rapidly as the World Wide Web has developed into a central means for sharing and disseminating information. The structure of tree-like semistructured data is not rigid. The most common instance of this type of data is XML. Applications endeavouring to access components of semistructured data are naturally inclined towards a recursive approach to navigate data on trees. However, conventional wisdom indicates that a set-oriented mechanism is necessary for database management systems to obtain good performance in the presence of large amounts of data. Our main objective in this thesis is to develop a set-oriented query execution scheme for XML data. We propose a system, called "Equate" (Execution of Queries Using an Automata Theoretic Engine), which intelligently utilises an automata rewriting scheme to transform a query language into an internal query plan with relational-like operators scheduled in a single process for a set-oriented execution. Our approach contains two phases. The first phase, set-oriented execution, performs queries on edges and binds any variables required. The second phase, reachability analysis, refines the result, filtering out any false matches, and collects sets of variable bindings into a final result structure. " A novel aspect of our approach is that our set-oriented execution, even for complex queries, requires only variants of the relational select, project, and union operators, but no joins.

Relevance is the critical criterion for valuing information. The usual requirements of valuable information resources are their accuracy, brevity, timeliness and rarity. This thesis points out that relevance has to be explicitly recognised as an important quality of information. Therefore, the theory of signs is adopted to enable a systematic study of the problem of relevance according to the branches of semiotics in order to clarify the concept of information. Relevance has several meanings according to the various disciplinary approaches including phenomenology, law, logic, information science, communication and cognition. These different concepts are discussed and criticised in two chapters. A new approach is proposed in which a universal concept of relevance is considered as an affordance. Therefore, all the approaches to relevance can be applied within the broader approach of the analysis of affordances. This approach not only encompasses all the underlying characteristics of relevance, it is also compatible with the assumptions of the logic of norms and affordances (NORMA). NORMA semantic analysis is used as a basis on which concepts of relevance are applied semiotically. Two case- studies are selected for testing these concepts which results in a guideline for practical application in a semiotic framework. The results from these case-studies confirm the practical importance of these concepts of relevance which can be systematically used in the analysis and design of information systems. It also reaffirms the underlying characteristics of relevance which exist in the context of social reality.

How can we enable conventionally-educated information systems (IS) developers to use a richer model of organisations and move towards an interpretive paradigm? The thesis of this research is that a way can be found by using metaphors for organisations as cognitive structuring devices during IS development. Two interpretive, idiographic studies explore whether and how some systems developers could work with a range of metaphors for organisations. Phase 1 of the fieldwork research involved the development of an information system for a small engineering company. Phase 2 involved the development of information systems for a local authority department, a hospital diabetes centre and a chain of DIY stores. The use of metaphors is analysed using a cognitive psychology theory of metaphor and analogy. It is found that the developers used a range of organisational metaphors. They also linked the mappings generated to IS development issues, showing that the metaphors had practical relevance. A prototype methodology, Multi-Metaphor Methodology, is created. Version 1 has a theoretical basis from previous IS research, organisation analysis and cognitive psychology. Learning outcomes from the two fieldwork studies lead to enhancements in Versions 2 and 3. The methodology is thus based on knowledge from both theory and action. The developers felt it was helpful and recommended its development should continue. Phase 1 used interpretive action research. Issues arising from Phase 1 lead to the proposal of three additional validity criteria: the extent of participation, students as co-researchers, and guarding against self or group delusion. Phase 2 used co-operative inquiry. It is concluded that IS action research can be improved by reference to the literature of cooperative inquiry, which better addresses method, participation, knowledge, and validity. It is also concluded that co-operative inquiry can be improved by adding validity criteria from the IS action research literature. Contributions to knowledge are made in the use of organisational metaphors and cognitive psychology theory, the development of a methodology, two interpretive studies and an examination of research methods and validity.

No description available.

Uganda has been considered one of Africa's few "success stories" over the past decade, an example of how a country can be transformed through a committed state bureaucracy. The thesis questions this view by looking at the experiences of development and change in a subparish in eastern Uganda. From this more local-level perspective, the thesis discusses the weakness of the state in the countryside, and incorporates the importance of religious and customary institutions. In place of a narrow view of politics, focused on reforms and policies coming from above, which rarely reach rural areas in a consistent or predictable way, the thesis describes political developments within a rural community. The thesis rests on two premises. First, that the state in rural Uganda has been too weak to support an effective bureaucratic presence in the countryside. Second, that politics at the local-level is an "open-ended" business, better understood through investigating a range of institutional spaces and activities, rather than a particular set of actions, or a single bureaucracy. Oledai sub-parish, which provides the empirical material for the thesis, was far removed from the idea of state-sponsored success described in the literature. V illagers had to contend with a history of violence, with recent impoverishment, and with the reality that the rural economy was unimportant in maintaining the structures of the government system. The thesis shows that the marginalisation of the countryside came at a time when central and local government structures had become increasingly reliant on funding from abroad. Aside from the analysing the weakness of the state bureaucracy, the thesis goes on to discuss broader changes in the life of the sub-parish, including the impact of a violent insurgency in the late 1980s. The thesis also looks at the role of churches and burial societies, institutions which have been largely ignored by the literature on political developments in Uganda. Religious and customary institutions, as well as the village court, provided spaces where political goals, such as settling disputes, building a career, or acquiring wealth, could be pursued.

In this dissertation we propose, test and develop a novel search interaction model to address two key problems associated with conducting an open-ended search task within a classical information retrieval system: (i) the need to reformulate the query within the context of a shifting conception of the problem and (ii) the need to integrate relevant results across a number of separate results sets. In our model the user issues just one highrecall query and then performs a sequence of more focused, distinct aspect searches by browsing the static structured context of a spatial-semantic visualization of this retrieved document set. Our thesis is that unsupervised spatial-semantic visualization can automatically classify retrieved documents into a two-level hierarchy of relevance. In particular we hypothesise that the locality of any given aspect exemplar will tend to comprise a sufficient proportion of same-aspect documents to support a visually guided strategy for focused, same-aspect searching that we term the aspect cluster growing strategy. We examine spatial-semantic classification and potential aspect cluster growing performance across three scenarios derived from topics and relevance judgements from the TREC test collection. Our analyses show that the expected classification can be represented in spatial-semantic structures created from document similarities computed by a simple vector space text analysis procedure. We compare two diametrically opposed approaches to layout optimisation: a global approach that focuses on preserving the all similarities and a local approach that focuses only on the strongest similarities. We find that the local approach, based on a minimum spanning tree of similarities, produces a better classification and, as observed from strategy simulation, more efficient aspect cluster growing performance in most situations, compared to the global approach of multidimensional scaling. We show that a small but significant proportion of aspect clustering growing cases can be problematic, regardless of the layout algorithm used. We identify the characteristics of these cases and, on this basis, demonstrate a set of novel interactive tools that provide additional semantic cues to aid the user in locating same-aspect documents.

Relying solely on Web browsers to navigate large Web sites has created some navigation problems for users. Many researchers have stressed the importance of improving site user orientation and have suggested the use of information visualisation techniques, in particular "site maps" or "overview diagrams" to address this issue. Link prediction and the semantic relatedness of Web pages have been incorporated into such site maps. This thesis addresses disorientation within Web sites by presenting a visualisation of the site in order to answer one of the three fundamental questions identified by Nielsen and others that users might ask when they become disoriented while navigating a Web site, namely, Where am I now? Where have I been? Where can I go next? A method for making link predictions, which is based on Markov chains, has been developed and implemented in order to answer the third question, "where can I go next?". The method utilises information about the path already followed by the user. In addition to link prediction, pages which are semantically similar to the "current" page are automatically identified using an approach which is based on lexical chains. The proposed approach for link prediction using an exponentially-smoothed transition probability matrix incorporating site usage data over a time period was evaluated by comparing with similar approach developed by Sarukkai. The proposed semantic relatedness approach using weighted lexical chains was empirically compared with an earlier approach developed by Green using synset weight vectors. In conclusion, this thesis argues that Web site link prediction and the identification of semantically-related Web pages can be used to overcome disorientation. The approaches proposed are demonstrated to be superior to earlier methods.

No description available.

No description available.