16,109 research outputs found
Concept-based Interactive Query Expansion Support Tool (CIQUEST)
This report describes a three-year project (2000-03) undertaken in the Information Studies
Department at The University of Sheffield and funded by Resource, The Council for
Museums, Archives and Libraries. The overall aim of the research was to provide user
support for query formulation and reformulation in searching large-scale textual resources
including those of the World Wide Web. More specifically the objectives were: to investigate
and evaluate methods for the automatic generation and organisation of concepts derived from
retrieved document sets, based on statistical methods for term weighting; and to conduct
user-based evaluations on the understanding, presentation and retrieval effectiveness of
concept structures in selecting candidate terms for interactive query expansion.
The TREC test collection formed the basis for the seven evaluative experiments conducted in
the course of the project. These formed four distinct phases in the project plan. In the first
phase, a series of experiments was conducted to investigate further techniques for concept
derivation and hierarchical organisation and structure. The second phase was concerned with
user-based validation of the concept structures. Results of phases 1 and 2 informed on the
design of the test system and the user interface was developed in phase 3. The final phase
entailed a user-based summative evaluation of the CiQuest system.
The main findings demonstrate that concept hierarchies can effectively be generated from
sets of retrieved documents and displayed to searchers in a meaningful way. The approach
provides the searcher with an overview of the contents of the retrieved documents, which in
turn facilitates the viewing of documents and selection of the most relevant ones. Concept
hierarchies are a good source of terms for query expansion and can improve precision. The
extraction of descriptive phrases as an alternative source of terms was also effective. With
respect to presentation, cascading menus were easy to browse for selecting terms and for
viewing documents. In conclusion the project dissemination programme and future work are
outlined
Searching and organizing images across languages
With the continual growth of users on the Web
from a wide range of countries, supporting
such users in their search of cultural heritage
collections will grow in importance. In the
next few years, the growth areas of Internet
users will come from the Indian sub-continent
and China. Consequently, if holders of cultural
heritage collections wish their content to be
viewable by the full range of users coming to
the Internet, the range of languages that they
need to support will have to grow. This paper
will present recent work conducted at the
University of Sheffield (and now being
implemented in BRICKS) on how to use
automatic translation to provide search and
organisation facilities for a historical image
search engine. The system allows users to
search for images in seven different languages,
providing means for the user to examine
translated image captions and browse retrieved
images organised by categories written in their
native language
User experiments with the Eurovision cross-language image retrieval system
In this paper we present Eurovision, a text-based system for cross-language (CL) image retrieval.
The system is evaluated by multilingual users for two search tasks with the system configured in
English and five other languages. To our knowledge this is the first published set of user
experiments for CL image retrieval. We show that: (1) it is possible to create a usable multilingual
search engine using little knowledge of any language other than English, (2) categorizing images
assists the user's search, and (3) there are differences in the way users search between the proposed
search tasks. Based on the two search tasks and user feedback, we describe important aspects of
any CL image retrieval system
Automatically attaching web pages to an ontology
This paper describes a proposed system for automatically attaching material from the world wide web to concepts in an ontology. The motivation for this research stems from the Diogene project, which requires the project's own databases of learning objects to be augmented with additional resources from the web. Two main approaches to this problem are being taken: one using ontology mapping, and another based on the conventional text search facilities of the web, covered in this paper. By generating queries based on the concepts in the ontology, the aim is to retrieve material from the web, and then filter it to ensure its proper correspondence with a concept. The Diogene system will be briefly outlined, before the query-generation system is described. A small pilot experiment, designed to provide some initial results and insight into the problem, is then presented
The combined approach to ontology-based data access
The use of ontologies for accessing data is one of
the most exciting new applications of description
logics in databases and other information systems.
A realistic way of realising sufficiently scalable ontology-
based data access in practice is by reduction
to querying relational databases. In this paper,
we describe the combined approach, which incorporates
the information given by the ontology into
the data and employs query rewriting to eliminate
spurious answers. We illustrate this approach for
ontologies given in the DL-Lite family of description
logics and briefly discuss the results obtained
for the EL family
Automatically organising images using concept hierarchies
In this paper we discuss the use of concept hierarchies, an approach to automatically organize a set of documents based upon a set of concepts derived from the documents themselves for image retrieval. Co-occurrence between terms associated with image captions and a statistical relation called subsumption are used to generate term clusters which are organized hierarchically. Previously, the approach has been studied for document retrieval and results have shown that automatically generating hierarchies can help users with their search task. In this paper we present an implementation of concept hierarchies for image retrieval, together with preliminary ad-hoc evaluation. Although our approach requires more investigation, initial results from a prototype system are promising and would appear to provide a useful summary of the search results
Concept hierarchy across languages in text-based image retrieval: a user evaluation
The University of Sheffield participated in Interactive ImageCLEF 2005 with a comparative user
evaluation of two interfaces: one displaying search results as a list, the other organizing retrieved images into
a hierarchy of concepts displayed on the interface as an interactive menu. Data was analysed with respect to
effectiveness (number of images retrieved), efficiency (time needed) and user satisfaction (opinions from
questionnaires). Effectiveness and efficiency were calculated at both 5 minutes (CLEF condition) and at final
time. The list was marginally more effective than the menu at 5 minutes (no statistical significance) but the
two were equal at final time showing the menu needs more time to be effectively used. The list was more efficient
at both 5 minutes and final time, although the difference was not statistically significant. Users preferred
the menu (75% vs. 25% for the list) indicating it to be an interesting and engaging feature. An inspection
of the logs showed that 11% of effective terms (i.e. no stop-words, single terms) were not translated and
that another 5% were ill translations. Some of those terms were used by all participants and were fundamental
for some of the tasks. Non translated and ill translated terms negatively affected the search, hierarchy generation
and, results display. More work has to be carried out to test the system under different setting, e.g. using
a dictionary instead of MT that appears to be ineffective in translating usersā queries that rarely are
grammatically correct. The evaluation also indicated directions for a new interface design that allows the user
to check query translation (in both input and output) and that incorporates visual content image retrieval to
improve result organization
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