From Text to Topics — Zigzagging Towards the Knowledgebase of Tang Civilization

Abstract
Afew years ago, the prospect of having access to a large
amount of digitized data promised to give a completely
new direction to the field of Chinese Studies. Although today
we have such databases as the Siku Quanshu (四庫全書¸)
Fulltext Database1, as well as many other texts, some of them
even freely available on the Internet, the benefits of this has
been limited. There are many reasons for this, not all of them
technical. Of the technical reasons, the limited, idiosyncratic
interface that each of these database provides, and the
unstructured data it operates on are probably the most important
ones.
The Knowledgebase of Tang Civilization is an attempt to
remedy this situation, at least for material relating to the Tang,
by providing a comprehensive electronic archive of information
about China during the period of the Tang dynasty (618-907
A.D.) in a way that allows new ways to access, analyze and
expand the information. Work on this Knowledgebase started
in 20032 with initial funding for 5 years. This presentation will
present some of the experiences gained in the first development
phase.
The design of the Knowledgebase uses a two layer model, that
distinguishes the 'information layer' from the 'resource layer'.
The organization of the information layer is based on the topic
map paradigm.3 to allow for the expression of ontology
subtrees, with links from the information layer back to the
resource layer, which will hold primary sources.
Its main point of access for researchers will be a web
application, but other interfaces will be developed.
Initially most of the information to be included will be textual,
but will in due time be enhanced by images, visual
reproductions of objects, digital maps and animations of events.
The distinguishing feature of the knowledgebase is the way information items are interconnected in a flexible and innovative
way.
The information in the knowledgebase will be organized along
the following information axis:
• Personal names, dates and activities of people of the Tang.
• Placenames and georeferences to there locations,
administrative geographical units, digital maps.
• Works created during the Tang, including texts, artefacts
and buildings
• Calendar and time
• Events of importance and influence
Obviously, many if not all information items will be accessible
through more than one of these axes; internally they are
cross-linked and form more of a web-like structure.
Additionally, these items are organized in hierarchical
ontologies. This allows to access the information also based
on their position within the hierarchy, or on the relation with
other items. For geographical locations, like a city for example,
such a hierarchy would consist of the upper administrative units
it belongs to; for persons this could consist of the family line,
but also the region of origin, the school or tradition of thought,
in the case of monks also the ordination line and line of
transmission.
The challenge in the first phase of the development, which will
be concluded by the time this presentation will be given, was
to design a way to bootstrap the Knowledgebase. For this
purpose, two dynastic histories (the Jiu Tang Shu (945) and the
Xin Tang Shu (1060)) and one chronologically arranged
historical account by Sima Guang (Zizhi Tongjian, 1084) have
been chosen to provide a basic set of information about the
Tang period. This idea relies on the fact, that the dynastic
histories do not only provide a day to day chronicle of court
affairs and other events, but also include monographs on a
variety of subject matters, including geography (with detailed
accounts of administrative units, their changes in size and
denomination, local production, population etc.), calendar
(including accounts of the calendar systems in use), ritual
observances, music, astronomy, offices, state finances, law and
a detailed bibliography of works known to have written in that
period. In addition to that, more than half of the text of the
official histories is taken up by biographic accounts. In the case
of the Tang, there are two such histories, since in the eyes of
Ouyang Xiu, the editor of the second, "new" history, the first
one had some defects in style and presentation.
The texts are encoded in XML using the TEI vocabulary. In a
first phase, only structural encoding was applied, so that the
texts could be accessed using XML technologies4 and could
be further processed. It was then started to add semantic markup
to allow for automatic extraction of information.
It should be obvious, that this collection provides rich material
that could be mined for inclusion in the Knowledgebase, but
the challenge was to find an efficient way to mine that
information, generate topics from them and relate them to each
other in the way outlined above. The presentation will focus
on the strategies employed and results achieved and will then
try to look at how to generalize these methods. It is also planned
to show a prototype of an interface, that allows further
enhancement of the data.
1. A database published by Chinese University Press, that includes
on 176 CD-ROMS an electronic text of the anthology Siku
Quanshu, which was compiled in China in the 17th century and
takes 1500 volumes in the modern reprint.
2. More information on this project can be found at <http://co
e21.zinbun.kyoto-u.ac.jp/> the website of the Institute
for Research in Humanities, COE 21 section
3. As defined in ISO 13250 (International Organization for
Standardization)
4. Most of this had been done semi-automatically. Just to give an
idea of the amount of the material, the size of the files with only
very basic encoding applied runs at this moment to well above 30
MB.
Bibliography
ISO. ISO/IEC 13250, Information technology - SGML
Applications - Topic Maps. Geneva: ISO, 2000.
Liu Xu. 舊唐書 (Jiu Tang Shu) (945). Beijing: Zhonghua
Shuju, 1975.
Ouyang Xiu. 新唐書 (Xin Tang Shu) (1060). Beijing:
Zhonghua Shuju, 1975.
Sima Guang. 資治通鑑 (Zizhi Tongjian) (1084). Beijing:
Zhonghua Shuju, 1956.
Wenyuange Siku quanshu dianziban. Hong Kong: Chinese
University Press, 1998.