8413372
Relating Complexity to Practical Performance in Parsing with Wide-Coverage Unification Grammars
The paper demonstrates that exponential complexities with respect to grammar size and input length have little impact on the performance of three unification-based parsing algorithms, using a wide-coverage grammar. The results imply that the study and optimisation of unification-based parsing must rely on empirical data until complexity theory can more accurately predict the practical behaviour of such parsers1.
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.
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.
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.
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.
16127213
Supporting interactive collaboration on the Web with CORK
Abstract The World Wide Web has served as a medium for collaboration since its inception. Web-based collaboration has, however, been dominated by systems supporting asynchronous activities such as sharing documents and participating in discussion forums. Supporting interactive, synchronous collaboration on the Web has proven much more challenging. In this paper we describe three of the challenges encountered in the context of supporting network-based collaboration among middle and high school science students: integrating synchronous and asynchronous modes of interaction, minimizing consumption of bandwidth, and adapting non-collaborative software components for collaborative use. We then present the Content Object Replication Kit, a toolkit for building interactive Java-based collaborative systems for use on the Web.
14643603
Making use is more than a matter of task analysis
I am pleased and honored that such an impressive group of commentators considered my book Making Use (Carroll, 2000) worthy of discussion and analysis. I would not expect, nor even prefer really, to have everyone agree with me. What would bother me, what would bother any author, is to not be read at all. Dan Diaper’s critical review and the commentaries by David Benyon/Catriona Macaulay, Tom Carey, and Fabio Paterno, will help to make that less likely! Many important themes are raised in Diaper (2002) review and in the commentaries. In this response I want to concentrate on refining a few of the main issues and distinctions. First, I briefly consider contrasts in values. I think that preferences for scenario-based design versus traditional task analytic methods reflect differences in the underlying world views and values of designers and researchers. To some extent, therefore, the issues in this discussion are not just technical, but paradigmatic and moral. Second, I consider the state of design practices in HCI and its implications for where onus lies in contemporary methodological argumentation and for what sorts of data are pertinent and required to address outstanding methodological issues. Finally, I consider the question of how task analysis, in the sense of structured task decomposition, might be reconstructed in the emerging paradigm of scenario-based design.
14401913
Community design of community simulations
We report on a participatory design workshop in which residents of a community collaborated in learning about and designing projects for a visual simulation environment. Nine participants (five middle school teachers, four senior citizens) first conducted a participatory evaluation of a tutorial developed for the Stagecast Creator simulation tool. They then worked in pairs to brainstorm ideas for Creator simulation projects that would help raise and promote discussion of issues relevant to their community. After sharing these ideas, each pair chose 2--3 simulation ideas to refine as a specification for subsequent implementation. We discuss the participants' learning and design activities, as well as their contributions to our long term goal of supporting cross-generational collaboration and learning through community simulation projects.
11544923
Unparsing RDF/XML
It is difficult to serialize an RDF graph as a humanly readable RDF/XML document. This paper describes the approach taken in Jena 1.2, in which a design pattern of guarded procedures invoked using top down recursive descent is used. Each procedure corresponds to a grammar rule; the guard makes the choice about the applicability of the production. This approach is seen to correspond closely to the design of an LL(k) parser, and a theoretical justification of this correspondence is found in universal algebra.
131770741
Structured Case: A Methodological Framework for Building Theory in Information Systems Research
This paper presents a methodological framework, structured-case, that assists IS researchers to undertake and assess theory building research within the interpretive paradigm, and explains its value in achieving convincing explanations that are strongly linked to both the research themes and data collected in the field.