ReQuest (Validating Semantic Searches) Norman Piedade de Noronha 16 th July, 2004
Dec 21, 2015
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Limitations in searching for information on the Web
Lack of syntax: Information is unstructured.
Lack of semantics: Machine processes do not understand the meaning of information.
Unable to properly filter information for users, leading to information overload.
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The Semantic Web (SW)
SW is a proposal for a Web of machine interpretable data.
Purpose: Automate user and computer tasks. Goal: Add structure and semantics to the
existing Web with metadata and ontologies.
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Metadata
Describes data about a web resource and not the actual content. Ex: Author, Date.
Resource Description Format (RDF) is the SW standard for metadata representation.
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Ontologies
Ontologies provide a shared and common understanding of concepts that can be communicated between people and heterogeneous distributed systems.
Ontologies are used in the SW as dictionaries, thesauri and vocabularies.
OWL (Web Ontology Language) is the W3C standard for ontologies representation.
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Semantic Web Searches
Ex: Contacting an author of a certain article in a particular newspaper.
Article Article’s Author Author’s Name Author’s Email
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Objectives
1. Build a Semantic Web search environment prototype: ReQuest.
2. Evaluate & compare searches against conventional search engines.
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Hypothesis
“Searches based on ontologies improve user satisfaction and reduce effort by eliminating irrelevant results.”
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Outline
Motivation & The Semantic WebReQuest– Architecture– Prototype
ReQuest for NewsValidation Conclusions & Future Work
ReQuest: Architecture
INTERFACE ENGIN
E
INTERFACE ENGIN
E
REPOSIT
ORY
REPOSIT
ORY
METADATA SUBSYSTEM
METADATA SUBSYSTEM
ONTOLOGY SUBSYSTEM
ONTOLOGY SUBSYSTEM
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Implementation
Ontology Subsystem – Java, RDF Schema
Metadata Subsystem – Java, RDF & RSS
Repository – SQL (PosGreSQL)
Interface Engine – HTML & Java Servlets
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Outline
Motivation & The Semantic Web
ReQuestArchitecture
Prototype
ReQuest for News
Validation
Conclusions & Future Work
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Configure new domain in ReQuest
1. Selecting Input Data.
2. Configuring ReQuest.
3. Defining Equivalences.
4. Launching New Domain.
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News Domain: Metadata Files
Newspaper– Created RDF File
Person– Created RDF File
Document– Imported from RSS News Feeds
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News Domain: Setup
Configuring ReQuest– Adding Ontology – Metadata Associations.– Defining periodicity of retrieval of metadata.
Defining Equivalences Launching a New Domain
– Retrieve and Process Ontologies– Generate template for interface.
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Examples of search queries
(Q1) Find the post office address for the publisher Público.
(Q9) How many distinct articles were published by Público about Futebol between the 5th of January, 2004 and the 7th of January, 2004.
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Individual Query Survey
How hard was the query to formulate?Did the semantic links help find the information?How long did it take to find the information?How relevant was the obtained information for your need?How many results were not interesting in the first page?Which search system was easier to use?
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User Feedback
Improve interface.
Rank search results.
Reduce information by providing a reduced version of results.
Search within results.
Search with properties from different contexts.
Domain search preferred to Global search.
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Hypothesis Validation
“Searches based on ontologies improve user satisfaction and reduce effort by eliminating irrelevant results.”
Measurements:1.Information Need Satisfaction.2.Effort Reduction.3.Irrelevant Results Reduction.
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Measure 1: Information Need Satisfaction
Only one user achieved greater success with Google.
Google’s results better in only one out of nine queries.
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Measure 2:Effort Reduction
Majority of users were successfully aided by ReQuest approximately 7 times, while only 20% managed to solve more than half of the tests with less effort with Google.
Some users did not produce a single test query where Google required less effort than ReQuest.
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Measure 3: Irrelevant Results Reduction
Only first page results were compared. 80% of users found fewer irrelevant results
with ReQuest than with Google. ReQuest was more precise than Google for
48.9% of all questions, while Google was more precise for 24.4%.
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Outline
Motivation & The Semantic Web
ReQuestArchitecture
Prototype
ReQuest for News
Validation
Conclusions & Future Work
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Conclusions
Positive Feedback:Searches based on ontologies improved user satisfaction
Reduced effort by eliminating irrelevant results.
Offering users the ability to select the search context is a more exact method for expressing the information need than key words.
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Future Work
More Extensive Validation. Domain searches enhanced with ability to
restrict values. Support OWL. Multilingual Searches.
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References
Presented at Interacção 2004 as
Norman Noronha, Mário J. Silva
Using the Semantic Web for Web Searches
July 2004.
Digital Deposit.
TUMBA – A Portuguese Search Engine.