Graeme Ritchie

Natural language interfaces to databases – an introduction

This paper is an introduction to natural language interfaces to databases (NLIDBS). A brief overview of the history of NLIDBS is first given. Some advantages and disadvantages of NLIDBS are then discussed, comparing NLIDBS to formal query languages, form-based interfaces, and graphical interfaces. An introduction to some of the linguistic problems NLIDBS have to confront follows, for the benefit of readers less familiar with computational linguistics. The discussion then moves on to NLIDB architectures, portability issues, restricted natural language input systems (including menu-based NLIDBS), and NLIDBS with reasoning capabilities. Some less explored areas of NLIDB research are then presented, namely database updates, meta-knowledge questions, temporal questions, and multi-modal NLIDBS. The paper ends with reflections on the current state of the art.

Some Empirical Criteria for Attributing Creativity to a Computer Program

Over recent decades there has been a growing interest in the question of whether computer programs are capable of genuinely creative activity. Although this notion can be explored as a purely philosophical debate, an alternative perspective is to consider what aspects of the behaviour of a program might be noted or measured in order to arrive at an empirically supported judgement that creativity has occurred. We sketch out, in general abstract terms, what goes on when a potentially creative program is constructed and run, and list some of the relationships (for example, between input and output) which might contribute to a decision about creativity. Specifically, we list a number of criteria which might indicate interesting properties of a program’s behaviour, from the perspective of possible creativity. We go on to review some ways in which these criteria have been applied to actual implementations, and some possible improvements to this way of assessing creativity.

A Comparison of Dominance Mechanisms and Simple Mutation on Non-stationary Problems

It is sometimes claimed that genetic algorithms using diploid representations will be more suitable for problems in which the environment changes from time to time, as the additional information stored in the double chromosome will ensure diversity, which in turn allows the system to respond more quickly and robustly to a change in the fitness function. We have tested various diploid algorithms, with and without mechanisms for dominance change, on non-stationary problems, and conclude that some form of dominance change is essential, as a diploid encoding is not enough in itself to allow flexible response to change. Moreover, a haploid method which randomly mutates chromosomes whose fitness has fallen sharply also performs well on these problems.

The Linguistic Analysis of Jokes

1. Introduction 2. Assumptions and Methodology 3. Linguistic preliminaries 4. Incongruity and its Resolution 5. Two Models of Incongruity-Resolution 6. The General Theory of Verbal Humour 7. Joke Similarity and Identity 8. Manipulating Interpretations 9. The Structure of Puns 10. Some Computational Studies 11. Pragmatic and Discourse Issues 12. Speculations on Joke Structure 13. Future Directions

AM: A case study in AI methodology.

Abstract Much artificial intelligence research is based on the construction of large impressive-looking programs, the theoretical content of which may not always be clearly stated. This is unproductive from the point of view of building a stable base for further research. We illustrate this problem by referring to Lenats am program, in which the techniques employed are somewhat obscure in spite of the impressive performance.

Computational rules for generating punning riddles

Riddles based on simple puns can be dassified according to the patterns of word, syllable or phrase similarity they depend upon. We have devised a formal model ofthe semantic and syntactic regularities underlying some of the simpler types of punning riddle. We have also implemented thispreliminary theory in a Computer program which can generate riddles from a lexicon containing general data about words andphrases; that is, the lexicon content is not customized to produce jokes. An informal, formative evaluation of the programs results by a set of human judges suggests that the riddles produced by this program are of comparable quality to those in general circulation among school children.

Current Directions in Computational Humour

Humour is a valid subject for research in artificial intelligence, as it is one of the more complex of human behaviours. Although philosophers and others have discussed humour for centuries, it is only very recently that computational work has begun in this field, so the state of the art is still rather basic. Much of the research has concentrated on humour expressed verbally, and there has been some emphasis on models based on “incongruity”. Actual implementations have involved puns of very limited forms. It is not clear that computerised jokes could enhance user interfaces in the near future, but there is a role for computer modelling in testing symbolic accounts of the structure of humorous texts. A major problem is the need for a humour-processing program to have knowledge of the world, and reasoning abilities.

Using genetic algorithms to create meaningful poetic text

This article presents a series of experiments in automatically generating poetic texts. We confined our attention to the generation of texts which are syntactically well-formed, meet certain pre-specified patterns of metre and broadly convey some given meaning. Such aspects can be formally defined, thus avoiding the complications of imagery and interpretation that are central to assessing more free forms of verse. Our implemented system, McGONAGALL, applies the genetic algorithm to construct such texts. It uses a sophisticated linguistic formalism to represent its genomic information, from which can be computed the phenotypic information of both semantic representations and patterns of stress. The conducted experiments broadly indicated that relatively meaningful text could be produced if the constraints on metre were relaxed, and precise metric text was possible with loose semantic constraints, but it was difficult to produce text which was both semantically coherent and of high quality metrically.

THE CONSTRUCTION OF A PUN GENERATOR FOR LANGUAGE SKILLS DEVELOPMENT

Since the early 1990s, there have been a number of small-scale computer programs that automatically constructed simple verbal jokes (puns), but none of these were fully developed systems that could be used for a practical application. We describe the building and testing of the STANDUP program – a large-scale, robust, interactive, user-friendly pun-generator (inspired by Binsteds JAPE program), which is aimed at allowing children, particularly those with communication disabilities, to develop their linguistic skills. The STANDUP system was designed in consultation with potential users and suitable experts, was rigorously engineered using public-domain linguistic data, and has a special purpose, child-friendly, graphical user interface. The software was tested successfully with real users (children with complex communication needs).

Evaluating the STANDUP Pun Generating Software with Children with Cerebral Palsy

The interactive STANDUP software was developed to provide children who use augmentative and alternative communication (AAC) with a “language playground.” The software provides appropriate functionality for users with physical, speech, and language impairments to generate and tell novel punning riddles at different levels of complexity. STANDUP was evaluated with nine children with cerebral palsy during an eight-week study. Results show that the participants were able to generate and tell novel jokes with minimal or no support. The use of STANDUP impacted favorably on general AAC use. The study results also suggested that STANDUP could potentially have a positive effect on social and pragmatic skills. Further research to investigate the impact of STANDUP on communication skills is proposed. Suggestions for future software development include providing users with opportunities to complete jokes and to integrate online dictionaries when new vocabulary is encountered.