Multi-Dimensional Inheritance

In this paper, we present an alternative approach to multiple inheritance for typed feature structures. In our approach, a feature structure can be associated with several types coming from different hierarchies (dimensions). In case of multiple inheritance, a type has supertypes from different hierarchies. We contrast this approach with approaches based on a single type hierarchy where a feature structure has only one unique most general type, and multiple inheritance involves computation of greatest lower bounds in the hierarchy. The proposed approach supports current linguistic analyses in constraint-based formalisms like HPSG, inheritance in the lexicon, and knowledge representation for NLP systems. Finally, we show that multi-dimensional inheritance hierarchies can be compiled into a Prolog term representation, which allows to compute the conjunction of two types efficiently by Prolog term unification.Comment: 9 pages, styles: a4,figfont,eepic,eps

Genre-based literacy pedagogy: the nature and value of genre knowledge in teaching and learning writing on a university first year media studies course

A thesis submitted to the Faculty of Humanities, Uniiversity of Luton, in partial fulfilment of the requirements for the degree of Doctor of PhilosophyIn the teaching and learning of literacy, descriptions of text have a problematic status as a result of the growing understanding of literacy as both a cognitive process and a social practice. In the teaching of academic subjects at university, student text is not usually an object of study. The research in this thesis draws on a language based theory oflearning to place textual description at the centre of the teaching and learning of both literacy and academic subjects at university. Participant observation and practice-based research methods were used to implement a form of text-oriented literacy teaching and to explore its compatibility with processes and practices orientations to literacy. Over an eighteen month period, systemic functional grammar was used to investigate and describe the texts of a film studies classroom and the descriptions were used in genre based literacy pedagogy. The effects of the pedagogy are measured in terms of students' performance in an end of course assignment, students' accounts of their writing processes, and student and subject-tutor perception of the text description and the pedagogy. In the thesis, a linguistic description of a key curriculum genre -a Taxonomic Film Analysis -is presented. An account is given of the pedagogy by means of which this essay genre was represented in the film studies classroom as a realisation of choices from linguistic, conceptual and activity systems. Systemic functional grammar-based text description is seen to have provided a means whereby a literacy tutor could collaborate with a subject tutor to provide a subject-specific form of literacy teaching which was evaluated as relevant by students and tutors. The account and the evaluation help to clarify the role that description of text can play in relation to processes and practices ofliteracy use in the teaching and learning of literacy in a film studies classroom and have implications for the teaching and learning of literacy at university more generally

Textual Economy through Close Coupling of Syntax and Semantics

We focus on the production of efficient descriptions of objects, actions and events. We define a type of efficiency, textual economy, that exploits the hearer's recognition of inferential links to material elsewhere within a sentence. Textual economy leads to efficient descriptions because the material that supports such inferences has been included to satisfy independent communicative goals, and is therefore overloaded in Pollack's sense. We argue that achieving textual economy imposes strong requirements on the representation and reasoning used in generating sentences. The representation must support the generator's simultaneous consideration of syntax and semantics. Reasoning must enable the generator to assess quickly and reliably at any stage how the hearer will interpret the current sentence, with its (incomplete) syntax and semantics. We show that these representational and reasoning requirements are met in the SPUD system for sentence planning and realization.Comment: 10 pages, uses QobiTree.te