Multiple Viewpoints for Tutoring Systems.

This thesis investigates the issue of how a tutoring system, intelligent or otherwise, may be designed to utilise multiple viewpoints on the domain being tutored, and what benefits may accrue from this. The issue was relevant to earlier systems, such as WHY (Stevens et al. 1979) and STEAMER (Hollan et al. 1984). The relevant literature is reviewed, and criteria which must be met by our implementation of viewpoints are established. Viewpoints are conceptualised as pre-defined structures which can be represented in a tutoring system with the potential to increase its effectiveness and adaptability. A formalism is proposed where inferences are drawn from a model by a range of operators. The application of this combination to problems and goals is to be described heuristically. This formulation is then related to the educational philosophy of Cognitive Apprenticeship. The formalism is tested and refined in a protocol analysis study which leads to the definition of three classes of operators. The viewpoint structure is used to produce a detailed formulation of the domain of Prolog debugging for novices, with the goal that students should learn how different bugs may be localised using different viewpoints. Three models of execution are defined, based on those described by Bundy et al. (1985). These are mapped onto a restricted catalogue of bugs by specifying a number of conventions which produce a simplified and consistent domain suited to the needs of novices. VIPER, a tutoring system which can itself accomplish and explain the relevant domain tasks, is described. VIPER is based on a meta-interpreter which produces detailed execution histories which are then analysed. An evaluation of VIPER is reported, with generally favourable results. VIPER is discussed in relation to the research goals, the usefulness of Cognitive Apprenticeship in supporting such a design, and possible future work. This discussion exemplifies the use of established student modeling techniques, the implementation of other viewpoints on Prolog, and the application of the design strategy to other domains. Claims are made in relation to the formulation of viewpoints, the architecture of VIPER, and the relevance of Cognitive Apprenticeship to the use of multiple viewpoints

'Wild above rule or art' : creation and critique

This thesis is an interrogation of the viability of transitive production, which I associate with the Aristotelian term hylomorphic. The central axiom of hylomorphic production that will be targeted for critique is that the agent of production must be distinguished absolutely from the product. The thesis follows the thought of production primarily-but not exclusively-in its characteristically modem instantiation in the Kantian transcendental. The argument seeks to demonstrate that the productive aspect of the operator of transitive production is incompatible with the transcendental element, and that Kant was himself increasingly aware of this problem. The Third Critique, under the rubric of an aesthetics, it will be argued, manifests this awareness in its problematic of a manifold of empirical laws. That this constitutes a difficulty for transcendent idealism means that the transcendental operators of the First Critique have failed to constitute experience in a relevant and important way. Furthermore, it is possible to see in some of the famous slogans of the Third Critique, an indication of another mode of production which is immune to the difficulties of the axiom of transitive production. In conclusion I suggest that the consequences of this new mode of intransitive production, associated with materiality, is destructive of the thought of the axiomatic otherworldliness of production operators. Production is not operated at all. Some suggestions are then made as to the explanation of the error embodied in the axiom of transitivity