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This thesis reports research undertaken in two rather distinct phases. Firstly, the thesis reports a study of cognitive processes involved in the task of 'concept identification': given sample instances of a concept, the task is to identify the concept. A computer model which successfully reproduces responses similar to those observed in human subjects is described. Secondly, this thesis reports the design of a case-based learning system REFINER. The system is a 'Learning Apprentice System' for differential diagnosis tasks, to aid the transfer of knowledge from a domain expert to a computer. Knowledge is obtained from the expert(s) in the form of cases which have been diagnosed or classified, and not in the traditional form of classification 'rules' which the experts often find hard to specify. The REFINER program is therefore a Knowledge Acquisiton System which helps an expert refine his knowledge in a more 'natural' way than having rules 'extracted'. Further, the system has the ability to point out that two classifications are not distinct, and can then suggest to the user ways in which the inconsistency might be resolved. Although the system has been used most extensively in the medical domain, it is essentially domain independent.

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This thesis is about 'User Involvement', a theme that is becoming the core of a growing body of research in the area of systems development and implementation. Although the value of user involvement in facilitating change is generally accepted, and has been specifically advocated by many recent system development approaches, its application has proved to be quite difficult. History is replete with cases where the effective implementation of user involvement has been hindered, partly by users who have been ill-equipped technically and psychologically to contribute positively to the systems development process, and partly by the prevailing organizational climate and the lack of an effective mechanism and methodology for participation. Problems experienced by offices in general - and in Egypt specifically - when introducing new office technology, as well as the need for further research on the subject of user involvement, have provided the impetus to conduct this research. A new approach to user involvement in office automation is presented in this thesis. The distinctive features of this approach include a focus on evolutionary learning and participation prior to the introduction of new computer-based office systems; a coherent strategy that addresses within its framework contextual variables at the individual, group and working environment level; a computer -aided mechanism that facilitates and guides the process of knowledge assimilation, user analysis of requirements, and group interaction; a capability of adapting to different organizational contexts; and finally, an interface to selected system development methodologies. The approach has three complementary dimensions: incremental knowledge acquisition, experience with the technology, and guided group interaction. To date the approach and mechanism have been implemented successfully in four institutions in Egypt. The scope and pattern of implementation have been influenced by the prevailing organizational and political circumstances at each user site. To draw on such experience in future implementations, a description of each case is provided.

The purpose of this study was to evaluate the impact of computer-based simulation on prelicensure senior second semester undergraduate baccalaureate nursing students' knowledge and satisfaction. The goal was to explore the current state of nursing education in relation to the nursing student's experience with interruptions and interruption management as interruptions and interruption management are an underexplored area of the nursing education experience, yet interruptions impact nursing performance and patient safety. Including effective interruption management in nursing education is the ultimate aim of this effort. The design of the study was a descriptive case study with mixed methods including quantitative and qualitative data collection and analysis. The quantitative analysis encompassed pretest and posttest drug calculation knowledge tests and a satisfaction survey. The qualitative portion of the study involved a focus group discussion relating to the nursing student's experience with interruptions and interruption management. The study results demonstrated that the participants were satisfied with the computer-based simulation. Furthermore, the results demonstrated that the professional nursing education of the study participants was devoid of interruption and interruption management education in the classroom, lab, and high-fidelity simulation. The themes that emerged from this study describe the current state of the second semester nursing student's experience with interruptions and interruption management and inform the need for interruption and interruption management education in professional nursing educational programs.

This thesis discusses how best to design, implement and evaluate a Case-Based Learning and Reasoning (CB-LR) model to assist accountants in identifying Top Management Fraud (TMF). There is no structured knowledge about TMF in the fonn of rules, only cases encountered by experienced auditors. The changing economic, financial and social environment has produced more fraud which at the same time has become increasingly complex to identify and isolate. Previous research shows that fraud has evaded auditors, and highlights a need for new computer-based learning and reasoning paradigms in this domain. Case-Based Reasoning (CBR) has been considered as an approach to building knowledge systems which involves reasoning about the current situation on the basis of pinpointing and resuscitating past instances. As with artificial intelligence in general, there is no standard readymade CBR method suitable for any domain or application: the challenge in CBR is to come up with methods that are suitable for problem-solving and learning in particular subject domains and for particular application environments. INCASE, a Top Management Fraud diagnostic application, has been designed with a specific methodology derived from Schank and Riesbeck's principles. INCASE works on the basis of the interviewees' concerns so that it can act as a 'stimulus agent' for decision support. The intention is for auditors to use it proactively in a conversational mode, focusing on learning and reasoning about the problem domain~ hence the use of the CB-LR model. Although evaluation methods relevant to traditional rule-based expert systems have been discussed in the literature, their emphasis on system issues was found to be inappropriate for this CB-LR application. Since there is no agreed and established method for evaluating a casebased tool, 'a new approach is discussed including verification (where the focus is on response accuracy of infonnation retrieval) and validation (where user judgement and satisfaction are key issues). One important component in the evaluation was an in-house questionnaire based on total quality management ideas. Findings from the evaluation of the TMF diagnostic system suggest that case-based learning and reasoning has a valuable part to play in assisting auditing profession in the detection of fraud

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Many designers find computer-based tools are not as effective during the early stages of design as manual sketching. However, to abandon the computer in these conceptual stages denies designers the computer‟s capability to translate and supplement imaginative design thinking. Recent design studies address conceptual design. What is the impact of computer-based drawing and sketching on designers‟ cognition and productive reasoning? This research focuses on the relationship between the characteristics of sketching using the drawing environment of the computer and the productivity of the conceptual design phase. I provide a theoretical framework that identifies and clarifies both sketching and productivity. Previous specialized studies are selective and sometimes only descriptive in defining this relationship. A review of these studies reveals a gap in our understanding of those aspects of sketching that relate to visualization, imagination and the generation of design ideas. The thesis addresses three objectives: (i) to build a comprehensive theoretical framework that on one hand defines the characteristics of sketching that might affect the generation of design ideas, and on the other hand defines the productivity of conceptual design and its indicators; (ii) to apply this framework in a practical study; and (iii) to extract implications for the relationship. To address the problem of computer-based sketching, I indentify the continuity within the dynamic field of images usually generated while designers sketch as the most effective characteristic of the computer sketching process. I establish a measure of continuity defined by (i) the degree of ease in projecting design images, (ii) the degree of continuity of displaying images due to changing the status of the design objects and due to navigation around the objects, (iii) the degree of provision of a holistic view (i.e., the total view of the design objects on the computer screen). Then I define productivity within this framework in terms of the cognitive operations of dialogical reinterpretation. When sketching, designers seem to perform key operations such as interpreting, reframing and restructuring. I present the case that a process rich with these cognitive operations is productive. The study makes use of the fields of free hand sketching, literature, cognitive psychology and Gestalt theory. Four indicators emerge from this study: the occurrence of pattern discovery, conceptual reinterpretation, alternation of thinking, and restructuring. I identify key variables that define the degree of continuity of the dynamic field of images which relate to designer‟s performance to verify their relationship with productivity. I study ten design participants who are given a design task that involves sketching with various CAD systems. The study involves 21 hours of recorded video analyzed using a method adapted from Goldschmidt's “linkography” tool for representing design protocols. I identify where patterns of relationships between variables exist, and where they do not apply. Not all the selected variables of continuity of the dynamic field of images, nor all the indicators of productivity in the conceptual design phase, support these patterns of relationships. This indicates that there is a special group of characteristics of sketching that maintain the pace of continuity within the dynamic field of images can improve the productivity in the conceptual phase.

Radical polymerisation (RP) has for many years been an industrially important process, and the kinetics of the process remains an active area of research. As polymerisation proceeds, converting monomer (small molecules) into polymer (long chain molecules), chemical species of a variety of chain lengths are produced. Recent work has pointed toward the fact that rate coefficients for polymerisation reactions (specifically, termination and propagation) are often dependent on the chain-length of the reacting species. The focus of this thesis is to study the effects of chain-length-dependent reactions on the kinetics of RP, by using computer-based modeling and comparing the results of such modeling with experimental data. This enables the understanding of otherwise inexplicable trends and the building of more mechanistically detailed and accurate models for RP kinetics. In Chapter 2, a new model for termination is developed, connecting observations and analyses of termination kinetics at short chain lengths (particularly small molecule studies) with other observations and analyses at long chain lengths (conventional RP kinetics studies) in order to construct a model for termination that is shown to be capable of coherently describing termination kinetics at any chain length. In Chapter 3, this new model for termination is tested at short chain lengths on polymerisations with large quantities of added chain transfer agent. With the inclusion of chain-length-dependent propagation in the model, the model for termination is validated. Chapter 4 is aimed at extending an existing reduced-variable, compact, 'universal' description of steady-state RP kinetics by incorporating all known chain-length dependent reactivities. This both increases computational efficiency over other approaches and provides easily evaluated, approximate analytical expressions for RP kinetics. This foundational theory is applied in Chapter 5 to reach a deeper understanding of the behaviour of the model, and show how experimental data may readily be analysed to extract information about chain-length-dependent termination kinetics. In Chapter 6, the effect of chain-length dependent reactivities on the important technique of single-pulse pulsed-laser polymerisation is investigated, and this technique is validated as the best experimental method for investigation of termination kinetics. In general, a central result of this thesis is that chain-length-dependent reactivities, when acknowledged and properly incorporated into models, can explain many phenomena in RP kinetics which otherwise seem difficult to account for. No exceptions to this principle have been found.