Information Technology Reference
In-Depth Information
3.2 Chronicle Analysis Tool
Data Filtering.
By filtering data, characteristic patterns will occur on a distri-
bution map. However, it is dicult to specify a keyword that represents a user's
interest. Even if there is no query, a distribution map representing an overview
of whole data will suggest candidate keywords to specify a user's interest.
Let us assume that a user sees the distribution map of whole data in the Dai-
Nihon Shiryo database
1
and finds an interesting keyword, ”gift.” Then, those
records that include the keyword ”gift” and contain information on an event
that occurred between 1550 and 1650 are selected from the database.
Distribution Map.
Figure 3 shows a distribution map of events related with
each person. The vertical axis represents the names of people in the order of
frequency, and the bar below a name shows the number of records that include
the specified person's name.
The distribution map represents personal activities concerning ”gift.” It is
easy to see the co-occurrence of Japanese emperors and men of power, e.g. Em-
peror Ogimachi - Nobunaga Oda, Emperor Goyozei - Ieyasu Tokugawa, etc. This
distribution suggests that relationships based on ”gift” indicate the relation of
authorities and powers.
Transition of Attribute Values.
A
topic sequence
[4] represents the content
of a document as a graphical plot of a document. It supports users' efforts to
guess the context (plot) of the document and to find desired parts of documents.
The records in the same cell of a distribution map are grouped together into
a document. Then, each document is visualized by a
word colony
[3], which
is a directed graph representing dependency relationships among terms in a
document. The
topic sequence
is formed by the connections of such
word colonies
.
Figure 4 shows four
topic sequences
representing human relations of two people
(Nobunaga Oda and Ieyasu Tokugawa) on the basis of ”gift” and ”battle.” The
major people in Nobunaga's human relations concerning ”gift” are authorities
at that time, such as Ashikaga Shogun and Emperor Ogimachi. In the case of
Ieyasu's human relations concerning ”gift,” the major people are authorities
only earlier in his life, after which Ieyasu's son took prominence for most of his
remaining years. Ieyasu was the first shogun in the Tokugawa shogunate. He
consolidated his son's position as his successor.
Topic sequences
concerning ”battle” show that Nobunaga is related with many
daimyos (territorial lords in pre-modern Japan), while Ieyasu is related with a
few daimyos. In light of knowledge about the territory these daimyos had con-
trol over, the visualization gives rise to the interpretation that Nobunaga fought
various enemies all over Japan, while Ieyasu fought a big enemy next to his ter-
ritory, which actually corresponds to history as we know it. These patterns help
users create new interpretations of history by exploring chronological records.
1
The most comprehensive collection of pre-modern Japanese historical materials.
