Facet-based Exploratory Search in Topic Maps

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Mervyn Warren
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1 Facet-based Search in Telematics Group, Institute of Computer Science Goethe-University, Frankfurt/Main, Germany 2008 / 10 / 16

2 Motivation and Objective The majority of based applications uses faceted classification Still, generic exploratory search interfaces for Topic Maps which shield the user from representational details have hardly been discussed In the following, we extend an RDF based approach [Delbru et al. 2006] discuss combinations with existing user interfaces

3 Search Search addresses information-seeking problems where a user needs to find out something about a domain but lacks specific (a-priori) knowledge In this situation, the user will usually submit tentative queries explore the retrieved information in order to selectively seek and passively obtain clues about his next steps

4 Faceted Classification A Faceted Classification System enables the assignment of multiple classifications (called facets) to an object the flexible ordering of these classifications in multiple ways w/o following pre-determined, taxonomic order A facet is a metadata attribute which should represent a single important characteristic of the classified objects

5 Facet-based Navigation as decision tree traversal Country Italy... Novel Scènesdela viedebohème... Contains... Lucca La Bohème (Leoncavallo) Source of La Bohème (Puccini) Birthplace of Libretto by Puccini, Giacomo Catalani, Alfredo Giacomo, Guiseppe Illica, Luigi Composed Wrote librettofor Tosca... Illica,Luigi... By iteratively choosing a facet (and associated restriction values), the information space is traversed

6 Automated Facet Identification In the context of heterogenous, dynamically changing datasets new information has to be (re-)classified on-the-fly In order to simplify the problem of missing/outdated facet-based classifications, a generic heuristic is needed

7 Facet Identification Entity (website) (website) Employer Company Employment (Employs/Employed by) Employee Person (job) Consultant/Programmer (Location) (Location) Person entity An entity is a subgraph of an information space, extracted by taking all adjacent vertices (objects) of a given vertex (subject)

8 Facet Identification View (website) (website) Employer Company Employment (Employs/Employed by) Employee Person (job) Consultant/Programmer (Location) (Location) Company entity Person entity A view is a set of entities of an information space

9 Facet Identification Facet (website) (website) Employer Company Employment (Employs/Employed by) (Location) (Location) Employee Person (job) Consultant/Programmer Company entity Person entity A facet is a set of equally labeled edges in a view

10 Facet Identification Restriction Value (website) (website) Employer Company Employment (Employs/Employed by) Employee Person (job) Consultant/Programmer (Location) (Location) Company entity Person entity The set of objects connected to a facet represent the restriction values

11 Contains Puccini, Giacomo Composed Country Birthplaceof Catalani, Alfredo La Bohème (Leoncavallo) Sourceof Novel Giacomo, Guiseppe Wrote librettofor La Bohème (Puccini) Librettoby Illica, Luigi Facet-based Navigation Balance Idea: the balance of a facet indicates its navigation efficiency (cf. tree traversal) Italy Lucca Tosca... Scènesdela viedebohème... Illica,Luigi... Computation: determine the (non-linear) normalised variance of the number of subjects for each object

12 Navigation Cardinality Idea: a suitable facet has a limited amount of restriction values to choose from Computation: determine the number of different objects (restriction values) for each facet normalise result using a function based on the gaussian density (cf. bell-shaped curve)

13 Navigation Frequency Idea: suitable facets occur frequently inside the collection the more distinct concepts are covered, the more useful the respective facet is in dividing the information space Computation: determine the number of subjects in the dataset for which the facet has been defined normalise result as a fraction of the total number of subjects

14 Navigation Example (1) (website) (website) Employer Company Employment (Employs/Employed by) Employee Person (job) Consultant/Programmer (Location) (Location) Company entity Person entity facet balance(f) card(f) freq(f) score Employment (website) (job) (location)

15 Navigation Example (2) (website) (website) Employer Company Employment (Employs/Employed by) Employee Person (job) Consultant/Programmer (Location) (Location) facet balance(f) card(f) freq(f) score Employment (website) (job) (location)

16 Additional Facet Classes Basic requirements of a facet browser: present the instances of all available types the relations need to be made explicit, selectable Previous example focused on relations between topics: association types occurrence types Search is also about filtering: topic types association roles types scope (scoping topics)

17 based on the /facet user interface [Hildebrand et al. 2006] Objectives: support both TMAPI1 and TMAPI2 interfaces provide light-weight module for multiple query engines

Topic Map Exploration Classic generic views (a) Associations (18) Internal Occurrences (4) Born in Bibliography Lucca Budden, Julian: "Puccini: His Life and Works", Oxford University Press (Oxford,

18 Topic Map Exploration Classic generic views (a) Associations (18) Internal Occurrences (4) Born in Bibliography Lucca Budden, Julian: "Puccini: His Life and Works", Oxford University Press (Oxford, 2002) Composed Sadie, Stanley (ed): "Puccini and His Operas", Macmillan (London, 2000) La Bohème Date of birth Edgar La fanciulla del West Date of death Gianni Schicchi Madama Butterfly Manon Lescaut External Occurrences (12) La rondine Article Suor Angelica - Scope: Web; Wikipedia Il Tabarro - Scope: Local; Store Norske Leksikon Tosca - Scope: Store Norske Leksikon; Web Turandot Gallery Le Villi - Scope: Local Died in Illustration Brussels - Scope: Local Exponent of Sound clip verismo - Scope: Centro studi Giacomo Puccini; Italian; Web Pupil of Web page Angeloni, Carlo - Scope: Local; Naxos Bazzini, Antonio - Scope: Naxos; Web Ponchielli, Amilcare - Scope: Web - Scope: OperaResource; Web (b) Web site Scope: Centro studi Giacomo Puccini; Italian; Web

19 Topic Map Exploration Stylized, facet-based display score= score= La Bohème Edgar La fanciulla del West Gianni Schicchi Madame Butterfly Composed by (Composed) Work Composer Web site Puccini, Giacomo Article Web page score= score= score= Budden, Julian: Puccini... Sadie, Stanley (ed): Puccini... Bibliography

Topic Map Exploration Selection tree and resulting tolog query Giacosa, Guiseppe $X Libretto by Audio recording $A... Composed by $B $C [Omnigator] Query results... Born in.

20 Topic Map Exploration Selection tree and resulting tolog query Giacosa, Guiseppe $X Libretto by Audio recording $A... Composed by $B $C [Omnigator] Query results... Born in... Located in Italy Query: libretto-by($x : opera, giacosa : librettist), audio-recording($x, $A), composed-by( $X : work, $B : composer), born-in( $B : person, $C : place), located-in($c : containee, italy : container)? A B C X Puccini, Giacomo Lucca Manon Lescaut OPD-1265 Catalani, Alfredo Lucca Loreley Puccini, Giacomo Lucca Madama Butterfly Puccini, Giacomo Lucca Tosca

21 Perspectives Navigation process for large information spaces can be improved by reducing the initial number of different facets associated with a view Additional metrics: concept of semantic distance between vertices [Andres/Naito2008] Minimal sub-graph of a given list of interested topics as starting point [Dichev/Dicheva/Fischer2007]

22 and Outlook The presented exploratory search interface for topic maps may enhance existing navigation aids It can be used to construct queries just by following links between concepts of interest, regardless of the underlying query engine/legend A stand-alone, TMAPI1/TMAPI2 based implementation with both basic text-based and graphical interfaces will be available shortly Currently, the forementioned functionality is being integrated in the user interface of an Eclipse based prototype for software engineering support

23 Thank you! to:

24 Example scenario in LTM notation [employer = "Employer"] [employee = "Employee"] [employment = "Employment" = "Employs" / employer = "Employed by" / employee] employment([person = "Person"] : employee, [company = "Company"] : employer) [website = "Website"] [location = "Location"] [job = "Job"] {company, website, " company-website {company, website, " product-website {company, location, " company-location {person, location, " person-location {person, job, [[consultant/programmer]]} person-job

25 Merging heterogenous topic maps Bibliography example [kcc_title = "The Knowledge-Creating Company"] [kcc_year = "1995"] [nonaka = "Ikujiro Nonaka"] [takeuchi = "Hirotaka Takeuchi"] reference( kcc_title :title, book :bibtype, kcc_year :year, nonaka :author, takeuchi :author ) [kcc :book = "The Knowledge-Creating Company"] { kcc, author, [[Ikujiro Nonaka]] } { kcc, author, [[Hirotaka Takeuchi]] } { kcc, year, [[1995]] }

26 How to combine different scopes? Problem of lack of formal semantics [Garshol2008] A user must get an explanation/decide how scoping topics are handled (and/or problem) Concepts from views of different scope can be handled in two ways: list only valid concepts using "merged" scope individual concepts retain their original scope Either way, facets representing scoping topics cannot easily be handled like other classes of facets (i.e., user cannot be shielded from representational details)

International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.

International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2. Editors: Status: Heuer, Hopmans, Oh, Pepper Editors' Working Draft Version: 0.5 Date: 2006-09-15 Issues: Templates: What functionality, what syntax? Flags and markers: what syntax? Clarify IRI terminology