16737045
Domain-Specific Sense Distributions and Predominant Sense Acquisition
Distributions of the senses of words are often highly skewed. This fact is exploited by word sense disambiguation (WSD) systems which back off to the predominant sense of a word when contextual clues are not strong enough. The domain of a document has a strong influence on the sense distribution of words, but it is not feasible to produce large manually annotated corpora for every domain of interest. In this paper we describe the construction of three sense annotated corpora in different domains for a sample of English words. We apply an existing method for acquiring predominant sense information automatically from raw text, and for our sample demonstrate that (1) acquiring such information automatically from a mixed-domain corpus is more accurate than deriving it from SemCor, and (2) acquiring it automatically from text in the same domain as the target domain performs best by a large margin. We also show that for an all words WSD task this automatic method is best focussed on words that are salient to the domain, and on words with a different acquired predominant sense in that domain compared to that acquired from a balanced corpus.
14652639
Ambiguity Packing in Constraint-based Parsing Practical Results
We describe a novel approach to 'packing' of local ambiguity in parsing with a wide-coverage HPSG grammar, and provide an empirical assessment of the interaction between various packing and parsing strategies. We present a linear-time, bidirectional subsumption test for typed feature structures and demonstrate that (a) subsumption- and equivalence-based packing is applicable to large HPSG grammars and (b) average parse complexity can be greatly reduced in bottom-up chart parsing with comprehensive HPSG implementations.
2252135
Disambiguating Nouns, Verbs, and Adjectives Using Automatically Acquired Selectional Preferences
Selectional preferences have been used by word sense disambiguation (WSD) systems as one source of disambiguating information. We evaluate WSD using selectional preferences acquired for English adjectivenoun, subject, and direct object grammatical relationships with respect to a standard test corpus. The selectional preferences are specific to verb or adjective classes, rather than individual word forms, so they can be used to disambiguate the co-occurring adjectives and verbs, rather than just the nominal argument heads. We also investigate use of the one-senseper-discourse heuristic to propagate a sense tag for a word to other occurrences of the same word within the current document in order to increase coverage. Although the preferences perform well in comparison with other unsupervised WSD systems on the same corpus, the results show that for many applications, further knowledge sources would be required to achieve an adequate level of accuracy and coverage. In addition to quantifying performance, we analyze the results to investigate the situations in which the selectional preferences achieve the best precision and in which the one-sense-per-discourse heuristic increases performance.
7294316
The Second Release of the RASP System
We describe the new release of the RASP (robust accurate statistical parsing) system, designed for syntactic annotation of free text. The new version includes a revised and more semantically-motivated output representation, an enhanced grammar and part-of-speech tagger lexicon, and a more flexible and semi-supervised training method for the structural parse ranking model. We evaluate the released version on the WSJ using a relational evaluation scheme, and describe how the new release allows users to enhance performance using (in-domain) lexical information.
3131824
From RAGS to RICHES: Exploiting the Potential of a Flexible Generation Architecture
The RAGS proposals for generic specification of NLG systems includes a detailed account of data representation, but only an outline view of processing aspects. In this paper we introduce a modular processing architecture with a concrete implementation which aims to meet the RAGS goals of transparency and reusability. We illustrate the model with the RICHES system -- a generation system built from simple linguistically-motivated modules.
656295
Word Sense Disambiguation Using Sense Examples Automatically Acquired from a Second Language
We present a novel almost-unsupervised approach to the task of Word Sense Disambiguation (WSD). We build sense examples automatically, using large quantities of Chinese text, and English-Chinese and Chinese-English bilingual dictionaries, taking advantage of the observation that mappings between words and meanings are often different in typologically distant languages. We train a classifier on the sense examples and test it on a gold standard English WSD dataset. The evaluation gives results that exceed previous state-of-the-art results for comparable systems. We also demonstrate that a little manual effort can improve the quality of sense examples, as measured by WSD accuracy. The performance of the classifier on WSD also improves as the number of training sense examples increases.
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.
9978523
Community collective efficacy: structure and consequences of perceived capacities in the Blacksburg Electronic Village
Bandura's social cognitive construct "perceived self-efficacy" has been used widely to understand individual behavior as a function of domain-specific beliefs about personal capacities. Collective efficacy is the extension of the self-efficacy construct to organizations and groups; it refers to beliefs about collective capacities in specific domains. Our research is investigating the use of collective efficacy in understanding attitudes and behaviors of members of proximal residential communities with respect to issues like attachment, engagement, and sociality, specifically as modulated by use of the Internet and community networks. This paper describes our analysis of the structure and external validity of the collective efficacy construct.
2198481
Participatory analysis: shared development of requirements from scenarios
Participatory design typically focuses on envisionment and evaluation activities. We explored a method for pushing the participatory activities further “upstream” in the design process, to the initial analysis of requirements. We used a variant of the task-artifact fi-arnework, carrying out a participatory claims analysis during a design workshop fm a project addressing collaborative science education. The analysis used videotaped classroom sessions as source material. The participant-teachers were highly engaged by the analysis process and contributed significantly to the analysis results. We conclude that the method has promise as a technique for evoking self-reflection and analysis in a participatory design setting.
14571844
The process of ISD methodology selection and use: a case study
This paper provides empirically-based explanations for the observed low, and partial, use of information systems development (ISD) methodologies. The research reported in this paper examines the process of methodology selection and use in an intensive field study of the early stages of systems development and notes ongoing adaptation of methodologies in response to changing contingencies. The paper concludes that, in many circumstances, methodology adaptation is a necessary part of successful systems development. It also suggests that deeper understanding of the attitudes of different stakeholders to selecting and using ISD methodologies may help to explain this adaptation.
10894513
Block-Level Consistency of Replicated Files