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). 32/33

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). 31/33

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: 30/33

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). 29/33

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. 28/33

Introduction – Web Search Engines Facets and Categories 27/33

Introduction – Web Search Engines Facets and Categories 26/33

Introduction – Web Search Engines Facets and 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. 25/33

Introduction – Web Search Engines Facets and Categories Selected pdf sub-category under Filetype category Only pdfs related to the search term are displayed 24/33

Introduction – Web Search Engines Facets and Categories 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” 23/33

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.” 22/33

Introduction – Web Search Engines Facets and Categories “Hodgkin Lymphoma” is directly related to the search term Introduction – Web Search Engines Facets and Categories “Follicular Lymphoma” is directly related to the search term Facets “Blood Cancer” is indirectly related to the search term 21/33

“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. 20/33

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. 19/33

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). 18/33

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. 17/33

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.” 16/33

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. 15/33

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. 14/33

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)) 13/33

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.” 12/33

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.” 11/33

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. 10/33

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 9/33

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. 8/33

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) 7/33

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 6/33

Conclusions The results obtained from analyzing the data as a whole indicates the following three significant findings: 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. 5/33

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.” 4/33

Conclusions Seems likely that the level of expertise may be a contributory factor in the facet search process. 3/33

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?” 2/33

Questions ? ? ? ? ? ? ? ? ? ? ?