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.
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.
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.
7723669
Better home shopping or new democracy?: evaluating community network outcomes
This is a perspective paper on community networks - socio-technical infrastructures supporting villages, towns, and neighborhoods. Community networking is well-established, world wide, and addresses critical societal issues, such as the “crisis of community” and the sociality of the Internet. However, community network projects have not emphasized evaluation. Relatively little is known about the economic, social, and psychological consequences of community networks for the individuals, groups, and communities served. Evaluating community networks is a momentous mutual opportunity for the development of CHI evaluation methodologies and for bringing technical CHI expertise to bear on societal issues.
23810734
Requirements Development in Scenario-Based Design
We describe and analyze the process of requirements development in scenario based design through consideration of a case study. In our project, a group of teachers and system developers initially set out to create a virtual physics laboratory. Our design work centered on the collaborative development of a series of scenarios describing current and future classroom activities. We observed classroom scenarios to assess needs and opportunities, and envisioned future scenarios to specify and analyze possible design moves. We employed claims analysis to evaluate design trade-offs implicit in these scenarios, to codify the specific advantages and disadvantages in achieving requirements. Through the course of this process, the nature of our project requirements has evolved, providing more information but also more kinds of information. We discuss the utility of managing requirements development through an evolving set of scenarios, and the generality of the scenario stages from this case study.
1566611
Managing evaluation goals for training
goals and are characteristically underresourced. In this article, we describe a framework for managing training evaluation in such contexts. We illustrate by example the feasibility of taking a broad approach toward training evaluation. Scriven [21] introduced the terms formative and summative in his classic work on the objectives and processes of instructional evaluation. Formative evaluation seeks to identify aspects of a design that can be improved. A typical implementation would be having users think aloud as they work through a tutorial to produce a real-time commentary on the nature of the learning experience. Each comment is tightly coupled to a specific design feature, facilitating the identification of problems and reasoning about design solutions. Summative evaluation seeks to gauge a design product. A typical implementation would be measuring time-on-task and error rate to guide decision-making about whether a training system (or the software it supports) should be produced and marketed, or purchased. Formative evaluation work succeeds to the extent that it identifies priorities for redesign and refinement, and all the more to the extent that it provides concrete guidance as to how that redesign and refinement should be executed. Summative evaluation work succeeds to the extent that it allows a design product to be located on various measurement scales with respect to other design products; the stronger the scale (i.e., ratio scale versus interval scale versus ordinal scale versus nominal scale), the better the summative evaluation. Scriven [21] also distinguished two basic types of evaluation method, intrinsic and pay-off :
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.
52799724
Comparative usability evaluation: critical incidents and critical threads