32981346
An Island Parsing Interpreter For The Full Augmented Transition Network Formalism
Island parsing is a powerful technique for parsing with Augmented Transition Networks (ATNs) which was developed and successfully applied in the HWIM speech understanding project. The HWIM application grammar did not, however, exploit Woods' original full ATN specification. This paper describes an island parsing interpreter based on HWIM, but containing substantial and important extensions to enable it to interpret any grammar which conforms to that full specification of 1970. The most important contributions have been to eliminate the need for prior specification of scope clauses, to provide more power by implementing LIFTR and SENDR actions within the island parsing framework, and to improve the efficiency of the techniques used to merge together partially-built islands within the utterance.This paper also presents some observations about island parsing, based on the use of the parser described, and some suggestions for future directions for island parsing research.
1627677
High Precision Extraction of Grammatical Relations
A parsing system returning analyses in the form of sets of grammatical relations can obtain high precision if it hypothesises a particular grammatical relation only when it is certain that the relation is correct. We operationalise this technique -in a statistical parser using a manually-developed wide-coverage grammar of English - by only returning relations that form part of all analyses licensed by the grammar. We observe an increase in precision from 75% to over 90% (at the cost of a reduction in recall) on a test corpus of naturally-occurring text.
12738746
Software support for practical grammar development
Even though progress in theoretical linguistics does not necessarily rely on the construction of working programs, a large proportion of current research in syntactic theory is facilitated by suitable computational tools. However, when natural language processing applications seek to draw on the results from new developments in theories of grammar, not only the nature of the tools has to change, but they face the challenge of reconciling the seemingly contradictory requirements of notational perspicuity and efficiency of performance. In this paper, we present a comparison and an evaluation of a number of software systems for grammar development, and argue that they are inadequate as practical tools for building wide-coverage grammars. We discuss a number of factors characteristic of this task, demonstrate how they influence the design of a suitable software environment, and describe the implementation of a system which has supported efficient development of a large computational grammar of English.
9629533
The Automatic Acquisition of Verb Subcategorisations and Their Impact on the Performance of an HPSG Parser
We describe the automatic acquisition of a lexicon of verb subcategorisations from a domain-specific corpus, and an evaluation of the impact this lexicon has on the performance of a “deep”, HPSG parser of English. We conducted two experiments to determine whether the empirically extracted verb stems would enhance the lexical coverage of the grammar and to see whether the automatically extracted verb subcategorisations would result in enhanced parser coverage. In our experiments, the empirically extracted verbs enhance lexical coverage by 8.5%. The automatically extracted verb subcategorisations enhance the parse success rate by 15% in theoretical terms and by 4.5% in practice. This is a promising approach for improving the robustness of deep parsing.
45352
A Practical Approach to Multiple Default Inheritance for Unification-Based Lexicons
This paper describes a unification-based lexicon system for NLP applications that incorporates mechanisms for multiple default inheritance. Such systems are intractable in the general case---the approach adopted here places a number of restrictions on the inheritance hierarchy in order to remove some of the sources of complexity while retaining more desirable properties. Implications of the design choices are discussed, comparisons are drawn with related work in computational linguistics and AI, and illustrative examples from the lexicons of German and English are given.
1954
Corpus Annotation for Parser Evaluation
We describe a recently developed corpus annotation scheme for evaluating parsers that avoids shortcomings of current methods. The scheme encodes grammatical relations between heads and dependents, and has been used to mark up a new publicdomain corpus of naturally occurring English text. We show how the corpus can be used to evaluate the accuracy of a robust parser, and relate the corpus to extant resources.
58199435
Usability engineering - scenario-based development of human-computer interaction
Usability Engineering: Scenario-Based Development of Human-Computer Interaction is a radical departure from traditional books that emphasize theory and address experts. This book focuses on the realities of product development, showing how user interaction scenarios can make usability practices an integral part of interactive system development. As you'll learn, usability engineering is not the application of inflexible rules; it's a process of analysis, prototyping, and problem solving in which you evaluate tradeoffs, make reasoned decisions, and maximize the overall value of your product.
8531327
Towards automatic shaping in robot navigation
Shaping is a potentially powerful tool in reinforcement learning applications. Shaping often fails to function effectively because of a lack of understanding about its effects when applied in reinforcement learning settings and the use of inadequate algorithms in its implementation. Due to these difficulties current shaping techniques require some form of manual intervention. We examine some of the principles involved in shaping and present a new algorithm for automatic transferral of knowledge, which uses the Q-values established in a previous task to guide exploration in the learning of a new task. This algorithm is applied to two different but related robot navigation tasks.
15595014
Notification and awareness: synchronizing task-oriented collaborative activity
People working collaboratively must establish and maintain awareness of one another's intentions, actions and results. Notification systems typically support awareness of the presence, tasks and actions of collaborators, but they do not adequately support awareness of persistent and complex activities. We analysed awareness breakdowns in use of our Virtual School system--stemming from problems related to the collaborative situation, group, task and tool support--to motivate the concept of activity awareness. Activity awareness builds on prior conceptions of social and action awareness, but emphasizes the importance of activity context factors like planning and coordination. This work suggests design strategies for notification systems to better support collaborative activity.
11499441
Matching RDF Graphs
The Resource Description Framework (RDF) describes graphs of statements about resources. RDF is a fundamental lower layer of the semantic web. This paper explores the equality of two RDF graphs in light of the graph isomorphism literature. We consider anonymous resources as unlabelled vertices in a graph, and show that the standard graph isomorphism algorithms, developed in the 1970's, can be used effectively for comparing RDF graphs. The techniques presented are useful for testing RDF software.
18081961
Designing our town: MOOsburg
MOOsburg is a community-oriented multi-user domain. It was created to enrich the Blacksburg Electronic Village (BEV) by providing real-time, situated interaction and a place-based model for community information. Three versions of MOOsburg have been developed: a classic text-based MOO, a MOO extended to drive a Web-browser, and a Java-based system. The most recent version of MOOsburg is fundamentally different from classic MOOs, supporting distributed system development and management and a direct manipulation approach to navigation. We are currently developing a variety of community-oriented applications, including a virtual science fair and a dispersed natural history museum.