Transcript The Use of Facets in Web Search Engines

By Elizabeth Milonas
Long Island University, New York
Introduction
• Faceted Classification has its roots in the Colon Classification
System originated by S.R. Ranganathan
• According to Ranganathan (1962, 81), facets are the fiber that
makeup a subject.
• Facets are used to display the various dimensions of a topic or
subject and like a Banyan Tree, represent topics in “all
directions simultaneously” (Shera 1951, 99-100).
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Introduction:
Facets and LIS
•
•
Facets are identified
as part of the facet
analysis process – a
process that brings
together all aspects of
the field of
knowledge by
itemizing the
concepts in more
detail and providing
more flexible
combination of terms
(Vickery 1966, 16).
Faceted classification
was initially used for
print media and later
became instrumental
in online LIS
database (Broughton
2006).
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Introduction – Facets and Websites
 Facets have been successfully implemented in the
browsing and search features of e-commerce sites,
digital museum portals and online library catalogs (La
Barre 2008) for the following inherent benefits:
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Introduction – Facets and Websites
(continued)
 Facets structure Web information (Vickery 2008).
 Facets present combination of terms providing
suggestions for navigational choices and supporting
flexible movement (Hearst 2008).
 Facets increase search success by expressing various
views of the search term guiding the searcher towards a
realization of the desired results (Vickery 2008).
 Facets and faceted classification also provide a successful
means of organizing and displaying the information on
the website (La Barre 2006).
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Introduction – Web Search Engines
Facets and Categories
 In the area of Web search engines, facets are used
alongside categories to help the Web searcher
 expand and narrow the search results and,
 provide a means of exploring the information
landscape.
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Introduction – Web Search Engines
Facets and Categories
CATEGORIES
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Introduction – Web Search Engines
Facets and Categories Facets
FACETS
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Introduction – Web Search Engines
Facets and Categories
 Categories:
 provide a list of documents and links that are related to
the search term and have the property of the category
selected
 for example, for the search term “Lymphoma,” when the
Web searcher selects the sub-category “pdf” under the
category “Filetype” only the pdf files related to the
search term “Lymphoma” will be displayed.
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Introduction – Web Search Engines
Facets and Categories
Selected
pdf subcategory
under
Filetype
category
Only pdfs
related to
the
search
term are
displayed
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Introduction – Web Search Engines
Facets and Categories
 Facets:
 display the search results by different aspects of the
search term
 for example if the search term is “Lymphoma” the facets
would be “Hodgkin lymphoma” or “Follicular
lymphoma”
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Introduction – Web Search Engines
Facets and Categories
 In Web search engines, facets can:
 Represent terms that are directly related to the search
term i.e. Hodgkin lymphoma
 Represent terms that are indirectly related to the search
term - i.e. blood cancer.
 Represent terms that are phase relations – two concepts
that are related to each other and to the search term, for
example “lymphoma in dogs.”
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“Hodgkin
Lymphoma” is
directly related to
the search term
Introduction – Web Search Engines
Facets and Categories Facets
“Follicular
Lymphoma” is
directly related
to the search
term
“Blood Cancer”
is indirectly
related to the
search term
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“Lymphoma in
dogs” is a phase
relation
The Study
• Study Objective:
• Examine the use of facets in Web search engines
• Determine whether the use of facets can
1) make the search process easier,
2) extend the search time, or
3) make the search process more confusing.
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The Study
 Four Web search engines were used; Google,
AltaVista, Exalead, and Excite
 Students using Exalead and Excite used facets to
conduct their search.
 Students using Google and AltaVista did not use
facets to conduct their search.
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The Study:
Participants
• Twenty nine
students from two
Long Island
University
academic
programs; the
Master’s in Library
and Information
Science (LIS) and
the Ph.D. in
Information
Studies (IS).
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The Study: Procedure
 Students were divided into two groups.
 Group one – Students used the facets found in Exalead
and Excite to search for two topics; “Social Network” and
“Lymphoma”
 Group two – Students used Google and AltaVista to
search for the same two topics (Social Network and
Lymphoma). These students did not use the facets
found in Google and AltaVista.
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The Study: Procedure
 Search terms: Social Network and Lymphoma
 72.4% of all students who participated were very or
somewhat familiar with the term “Social Network.”
 51.7% of all the students who participated were very or
somewhat familiar with the term “Lymphoma.”
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The Study: Procedure
 Questionnaire:
 Students were given a questionnaire that required them
to rate their Web search process.
 The questionnaire utilized a four-point Likert scale.
 Students were asked questions concerning the ease of
search process, search time and confusion during the
search process.
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The Study: Results
 Factorial analysis and T-tests:
 2x2 and 2x2x2 factorial analysis was performed.
 T-tests were conducted to determine whether the
observed differences were statistically significant.
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The Study: Results
 Factors:
 2x2 factors: Search term (two level: Social Network and
Lymphoma) and Search engine type (two levels: facet
and non-facet).
 2x2x2 factors: Search term (two levels: Social Network
and Lymphoma), Search engine type (two levels: facet
and non-facet) and type of student (two level: Master’s
(LIS) and Doctoral (IS))
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The Study: Results
 Statistically significant results from the 2x2 factorial
analysis (Exalead and Excite)
 Students found facets made the search process easier
whether searching for the familiar term “Social
Network” or the unfamiliar term “Lymphoma.”
 Students using facets found that their search time was
extended when searching for the familiar term “Social
Network” but not when searching for the unfamiliar
term “Lymphoma.”
 Students using facets found that their search process
was not confusing when searching for the familiar term
“Social Network.”
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The Study: Results
 Statistically significant results from the 2x2x2 factorial
analysis (Exalead and Excite)
 When searching for the familiar term ” Social Network” IS
students found that the use of facets did not make the search
process easier while LIS students found that the use of facets
did make the search process easier.
 Both IS and LIS students found the use of facets extended the
search time when searching for the familiar term “Social
Network” but did not extend the search time when searching
for the unfamiliar term “Lymphoma.”
 IS students found facets made the search process more
confusing when searching for the familiar term “Social
Network” while LIS students found facets did not make the
search process more confusing when searching for the term
“Social Network.”
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Analysis: Ease of search process
 Analysis of the data as a whole shows that the use of
facets made the search process easier when searching
for either familiar or unfamiliar topics.
 This finding is consistent with findings of the Yee et al.
(2003) and the Kules and Shneiderman (2008) studies.

Results from both studies indicated that facet search
interfaces are easier to use than non-facet search interfaces.
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Analysis: Ease of search process
 Analysis of the data from the two groups (IS and LIS)
using facets to search for the familiar term “Social
Network” indicates that IS students found facets did
not make the search process easier while LIS students
found that facets did make the search process easier.
 Plausible reason – Level of expertise of LIS and IS
students in terms of facet utilization
 Uddin and Janecek (2007) – non-expert users will have
difficulty using a faceted system because of lack of
experience
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Analysis: Search time
 Analysis of the data as a whole as well as the data from
the two groups indicates that when searching for a
familiar topic, the use of facets extended the search
time, however when searching for an unfamiliar topic,
the use of facets did not extend the search time.
 Familiar topics - the suggestions for navigational choices
will afford the participants the mechanism for deeper
exploration and discovery (Hearst 2008) and as a result
extend the search time.
 Unfamiliar topics – may be satisfied with the top level
search results and may not choose to delve deeper into
the topic.
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Analysis: Confusion during search
process
 Analysis of data as a whole shows that participants
found the use of facets did not cause confusion when
searching for a familiar topic.
 Facets allow users to move through the information
space without confusion (Hearst 2008)
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Analysis: Confusion during search
process
 Analysis of the two groups showed IS students found
facets made the search process more confusing when
searching for the familiar term. LIS students found
that facets did not make the search process more
confusing.
 Level of expertise may also play a role in terms of
confusion
 Time constraint may also impose an added pressure that
contributed to the feeling of discomfort and ultimately
the feeling of confusion.

Uddin and Janecek (2007) – non-expert users require more
time to understand faceted interfaces
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Conclusions
 The results obtained from analyzing the data as a whole
indicates the following three significant findings:
1.
2.
3.
Facets make the search process easier whether searching for
familiar or unfamiliar topics
When using facets it takes longer to search for familiar than
unfamiliar topics
When searching for familiar topics facets do not cause
confusion
 Findings 1 and 3 are well supported in the literature
(Denton 2009, Hearst 2008, Kules and Shneiderman 2008
Uddin and Janecek 2007).
 Finding 2 is not supported in the literature.
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Conclusions
 A comparison of study data from the two groups of
students (IS and LIS) showed a discrepancy between
the groups:
 IS students found that facets did not make the search
process easier and were confused when searching for the
familiar term “Social Network”
 LIS students found that facets did make the search
process easier and were not confused when searching for
the familiar term “Social Network.”
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Conclusions
 Seems likely that the level of expertise may be a
contributory factor in the facet search process.
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Future Study
 Explore the findings of this study.
 “Does the level of expertise have an impact on the use of
facets in the Web search process?”
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Questions
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