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.

1. Defining Domain-Specific Facets for Topic Maps
With TMQL Path Expressions
Sven Windisch
Dr. Lutz Maicher
Topic Maps Lab
Natural Language Processing Group
Computer Science Department
University of Leipzig
September 30, 2010
Sven Windisch, Dr. Lutz Maicher (Topic Maps Lab) September 30, 2010 1/23

2. 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

3. 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

4. Definition of facets
Facets are . . .
. . . clearly defined, mutually exclusive, and collectively exhaustive aspects,
properties or characteristics of a specific subject.
Example
Some person has a name, a date of birth and a birthplace. These three
characteristics are mutually exclusive and collectively exhaustive. They are
facets of this person.
Sven Windisch, Dr. Lutz Maicher (Topic Maps Lab) September 30, 2010 4/23

5. Mathematical Definition
Any facet can be described as a triple, consisting of
the parent identifier id(t) (i. e. whose Topics facet is this)
the name of the facet n (e. g. Department, Format, Binding)
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

6. Famous facet examples
Yelp lists lots of different burgers in San Francisco.
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

8. Facettable Elements of a Topic
Names
Names are very useful, but need careful spellchecking.
Special Name types (e.g. Forename, Surname) provide a more concise
classification.
Occurrences
Occurences with short values are fine for faceting.
Again, careful spellchecking is necessary.
Sven Windisch, Dr. Lutz Maicher (Topic Maps Lab) September 30, 2010 8/23

9. Facettable Elements of a Topic
Roles
A Topic plays a specific Role, or not. Roles can therefore be used as
flag-like facets.
Topic Types
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

10. Sven Windisch, Dr. Lutz Maicher (Topic Maps Lab) September 30, 2010 10/23

11. Don’t they come automagically?
Automatic generation of generic facets is possible (Ueberall et al. 2008).
But: Information needs of users are highly domain specific, while generic
facets are not.
Domain specific facets must cover more than the the Topics
characteristics.
Sven Windisch, Dr. Lutz Maicher (Topic Maps Lab) September 30, 2010 11/23

12. 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

13. Why TMQL?
TMQL makes navigating through a Topic Map very easy
But: Full TMQL is much too powerful for our requirements. The path
expressions can do the whole job.
Definition
A path expression represents a sequence of navigation steps through the
abstract bidirectional graph of a Topic Map. Starting from given values (atoms
or items in a Topic Map), navigation steps along defined axes within the
context map compute new values.
Sven Windisch, Dr. Lutz Maicher (Topic Maps Lab) September 30, 2010 13/23

14. How to Define a Facet
Any facet definition resembles a simple path expression with the following
limitations
The starting element must be a Topic that serves as Topic type for other
Topics.
The possible result values are restricted to strings, because the names
and values of facets must be human readable.
The given Topic type identifier is replaced with the respective identifier of one
of the instances. The TMQL expression is then executed and the result is
stored as the facets value.
Sven Windisch, Dr. Lutz Maicher (Topic Maps Lab) September 30, 2010 14/23

15. 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

16. 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

17. 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

18. 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

19. 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

20. 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

21. 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
http://psi.example.com/person is replaced by
http://psi.example.com/Sven_Windisch
The given query is executed, the result is Leipzig
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

22. 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

23. Conclusions
Domain-specific facets are useful wherever facets must link deeper.
TMQL does a wonderful job for defining domain-specific facets.
Defining domain-specific facets is easy.
The used Topic Map must be well modeled and spellchecked.
Outlook
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