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The automatic generation of facets works fairly bad for fine-modeled ontologies, in which not all information concerning a single Topic is available through occurrences and direct associations. In this paper, we share our conception of using TMQL path expressions for the definition of domain-specific facets by means of using standard-based Topic Maps technologies. The generated facets must be evaluated, even though they are defined manually by a domain expert. We therefore propose metrics for automatic evaluation of the defined facets, as well as a mechanism for using automatically stored user feedback.
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Defining Domain-Specific Facets for Topic MapsWith TMQL Path Expressions
Sven WindischDr. Lutz Maicher
Topic Maps LabNatural Language Processing Group
Computer Science DepartmentUniversity of Leipzig
September 30, 2010
Sven Windisch, Dr. Lutz Maicher (Topic Maps Lab) September 30, 2010 1/23
Agenda
Introduction to Facets in Topic Maps
Defining Domain-Specific Facets With TMQL
A Short Example
Conclusions and Outlook
Sven Windisch, Dr. Lutz Maicher (Topic Maps Lab) September 30, 2010 2/23
Overview
Introduction to Facets in Topic Maps
Defining Domain-Specific Facets With TMQL
A Short Example
Conclusions and Outlook
Sven Windisch, Dr. Lutz Maicher (Topic Maps Lab) September 30, 2010 3/23
Definition of facets
Facets are . . .
. . . clearly defined, mutually exclusive, and collectively exhaustive aspects,properties or characteristics of a specific subject.
ExampleSome person has a name, a date of birth and a birthplace. These threecharacteristics are mutually exclusive and collectively exhaustive. They arefacets of this person.
Sven Windisch, Dr. Lutz Maicher (Topic Maps Lab) September 30, 2010 4/23
Mathematical Definition
Any facet can be described as a triple, consisting of
I the parent identifier id(t) (i. e. whose Topics facet is this)
I the name of the facet n (e. g. Department, Format, Binding)
I the value of the facet v (e. g. Paperback, Hardcover )
f = (id(t),n,v)
Sven Windisch, Dr. Lutz Maicher (Topic Maps Lab) September 30, 2010 5/23
Famous facet examples
I Yelp lists lots of different burgers in San Francisco.
I The facets help you with choosing the one place that fits your need best.
Sven Windisch, Dr. Lutz Maicher (Topic Maps Lab) September 30, 2010 6/23
Facettable Elements of a Topic
NamesI Names are very useful, but need careful spellchecking.
I Special Name types (e.g. Forename, Surname) provide a more conciseclassification.
OccurrencesI Occurences with short values are fine for faceting.
I Again, careful spellchecking is necessary.
Sven Windisch, Dr. Lutz Maicher (Topic Maps Lab) September 30, 2010 8/23
Facettable Elements of a Topic
RolesI A Topic plays a specific Role, or not. Roles can therefore be used as
flag-like facets.
Topic TypesI Types of Topics are useful for distinguishing different kinds of search
results.
Sven Windisch, Dr. Lutz Maicher (Topic Maps Lab) September 30, 2010 9/23
Sven Windisch, Dr. Lutz Maicher (Topic Maps Lab) September 30, 2010 10/23
Don’t they come automagically?
I Automatic generation of generic facets is possible (Ueberall et al. 2008).
I But: Information needs of users are highly domain specific, while genericfacets are not.
I Domain specific facets must cover more than the the Topicscharacteristics.
Sven Windisch, Dr. Lutz Maicher (Topic Maps Lab) September 30, 2010 11/23
Overview
Introduction to Facets in Topic Maps
Defining Domain-Specific Facets With TMQL
A Short Example
Conclusions and Outlook
Sven Windisch, Dr. Lutz Maicher (Topic Maps Lab) September 30, 2010 12/23
Why TMQL?
I TMQL makes navigating through a Topic Map very easy
I But: Full TMQL is much too powerful for our requirements. The pathexpressions can do the whole job.
DefinitionA path expression represents a sequence of navigation steps through theabstract bidirectional graph of a Topic Map. Starting from given values (atomsor items in a Topic Map), navigation steps along defined axes within thecontext map compute new values.
Sven Windisch, Dr. Lutz Maicher (Topic Maps Lab) September 30, 2010 13/23
How to Define a Facet
Any facet definition resembles a simple path expression with the followinglimitations
I The starting element must be a Topic that serves as Topic type for otherTopics.
I The possible result values are restricted to strings, because the namesand values of facets must be human readable.
The given Topic type identifier is replaced with the respective identifier of oneof the instances. The TMQL expression is then executed and the result isstored as the facets value.
Sven Windisch, Dr. Lutz Maicher (Topic Maps Lab) September 30, 2010 14/23
Overview
Introduction to Facets in Topic Maps
Defining Domain-Specific Facets With TMQL
A Short Example
Conclusions and Outlook
Sven Windisch, Dr. Lutz Maicher (Topic Maps Lab) September 30, 2010 15/23
Example Topic Map
Mission: Create an office-location-facet for every person.
Sven Windisch, Dr. Lutz Maicher (Topic Maps Lab) September 30, 2010 16/23
Navigating the Topic Map
http://psi.example.com/person
>> traverse http://psi.example.com/mailing-address
>> traverse http://psi.example.com/container-containee-address
>> characteristics tm:name
Sven Windisch, Dr. Lutz Maicher (Topic Maps Lab) September 30, 2010 17/23
Navigating the Topic Map
http://psi.example.com/person
>> traverse http://psi.example.com/mailing-address
>> traverse http://psi.example.com/container-containee-address
>> characteristics tm:name
Sven Windisch, Dr. Lutz Maicher (Topic Maps Lab) September 30, 2010 18/23
Navigating the Topic Map
http://psi.example.com/person
>> traverse http://psi.example.com/mailing-address
>> traverse http://psi.example.com/container-containee-address
>> characteristics tm:name
Sven Windisch, Dr. Lutz Maicher (Topic Maps Lab) September 30, 2010 19/23
Navigating the Topic Map
http://psi.example.com/person
>> traverse http://psi.example.com/mailing-address
>> traverse http://psi.example.com/container-containee-address
>> characteristics tm:name
Sven Windisch, Dr. Lutz Maicher (Topic Maps Lab) September 30, 2010 20/23
From TMQL to Facets in Three Simple Steps
http://psi.example.com/person
>> traverse http://psi.example.com/mailing-address
>> traverse http://psi.example.com/container-containee-address
>> characteristics tm:name
I http://psi.example.com/person is replaced byhttp://psi.example.com/Sven_Windisch
I The given query is executed, the result is Leipzig
I A new facet is created:(http://psi.example.com/Sven_Windisch, Office Location, Leipzig)
Sven Windisch, Dr. Lutz Maicher (Topic Maps Lab) September 30, 2010 21/23
Overview
Introduction to Facets in Topic Maps
Defining Domain-Specific Facets With TMQL
A Short Example
Conclusions and Outlook
Sven Windisch, Dr. Lutz Maicher (Topic Maps Lab) September 30, 2010 22/23
ConclusionsI Domain-specific facets are useful wherever facets must link deeper.
I TMQL does a wonderful job for defining domain-specific facets.
I Defining domain-specific facets is easy.
I The used Topic Map must be well modeled and spellchecked.
OutlookI Release: Maiana prototype in October, complete search engine at the
end of 2010
Sven Windisch, Dr. Lutz Maicher (Topic Maps Lab) September 30, 2010 23/23
