Trend Information Extraction based on Relative Expression
participated on MuST T2N Subtask
Yasuhiro Uenishi

Fumito Masui

Abstract

Tatsuaki Matsuba
Mie UniversityAtsuo Kawai

Basic Elements (Quadruplet)This paper describes a system participating in the MuST
T2N subtask. To the participating system, we applied themethod of implicit trend information extraction utilizing
relative expressions such as ``0.1%増(grew 0.1%)'', ``前年(previous year)'' and ``過去最高(maximum)''. Relative
differences and numerical changes in trend information canbe signified by relative expressions. The system extracts
elements of four types by pattern-based rules considering
th relative
thel ti expression.
i Th
The extractedt t d element
lt isi comparedd
with the query word by identifying the synonym of theelements utilizing an EDR dictionary and some synonym
databases.
Some experiments were conducted with the MuST T2N
formal run test collection. Although the results showedprecision of 0.220 and recall of 0.029 totally, the outcomesof additional evaluations suggested the fundamental process
performs effectively.

Naoki Isu

Relative Expression and QuadrupletDocument¾On the basis of the MuST definition, we defined a quadruplet,
which is a set of four basic elements: name, par, date and val.
In MuST corpus, the four elements are tagged.

1999年のパソコン出荷台数は前年比36.7%増のRelative Expression

1083万台となった。

(In 1999, PC shipment volume grew 36.7% over the previous
year to 10.83 million units.)

Extraction of quadruplets
Document set

Explicit Quadruplet
par
name

Quadruplet set

パソコン出荷数(PC shipment volume)

name

par

dateval

パソコン出荷数(PC shipment volume)

ソニー(SONY)

1998年(1998)

30万台(300,000 units)

date1999年

Φ(1999) (10.83 million units)

Implicit Quadruplet
par
nameVisualization

パソコン出荷数Graphdate
1998年

Φ(PC shipment volume)val
1083万台

val
792万台

Reasoning theother quadruplet(1998) (7.92 million units)

System Overview
System Architecture
Query WordUnit

TaggedCorpus

module1

Extraction
Patterns(6994 patterns)

Basic Element Extraction
module2

Quadruplet Complementation

EDR
Dictionary

module3

Headword
DB(142 words)

Component Validation

Relative
Word DB(156 words)

module4

Implicit Quadruplet Generation

ReasonRules

Basic Element Extraction

Quadruplet Complementation¾Utilizing extraction patterns, basic elements for quadruplets
and a relative expression are extracted from tagged corpus.
Tagged Corpus¾The elements which can be extracted using the extraction
patterns are complemented.

日本電子工業振興協会が<date>15日</date>、<date>2006年</date>のパソコン国内実績を発表した。<name>パソコン出荷数</name>は<date>前年</date>比<rel>1.4%</rel>減の<val>1326万台</val>だった。

(On <date>9th</date>, JEIDA reported the PC shipments in<date>2006</date>. <name>The PC shipment volume</name>declined <rel>1.4%</rel>rel 1.4% /rel from <date>thedate the previous year</date>year /dateto <val>13.26 million units</val>.
Extraction Pattern<name> は <date> 比 <rel> 減の <val>(<name> declined <rel> from <date> to <val>)
Quadruplet
par

パソコン出荷数val
1326万台(PC shipment volume)(13.26 million units)

namedateComponent Validation¾The quadruplets that relate to the query word are selected. To select the quadruplets
related to a query word, components of the name element and the query word arevalidated.
¾We assumed that both a name element and a query word also consist of a headword(a unit of trend) and a specifier (a subject of trend).
¾If the checking components (specifier and headword) succeeds, the name element
relates to the query word. Headword is checked using headword database. Specifier
is checked using EDR dictionary and relative word database.
¾In the following cases, the element-derived specifier is relevant to
the query-derived specifier.
specifier If the name element is identical to the headword
headword,
the par element becomes a specifier.
8 Both specifiers are identical concept. (Ex1 and Ex2)
8 The element-derived specifier is the hyponym of
the query-derived specifier. (EX3)8 The element-derived specifier is the concept relevantto the query-derived specifier. (Ex4)
If the name element consists of only a headword anda quadruplet does not include the par element,
Component of Name Element and Query Word
the specifier is checked based on
Name Element or Query Word
SpecifierHeadwordco-occurrence in a sentence.
パソコン出荷台数
パソコン
出荷台数(PC shipment volume)(PC)(shipment volume)
8 The query-derived specifier is found
ビール出荷数量
ビール
出荷数量(Thequantityofbeershipped)(beer)(Theshippedquantity)
ahead of a part matched with the政党支持率
政党支持率extraction pattern in a sentence. (Ex5) (Approval rating for political parties) (Political parties) (Approval rating)name : The nearest name element ahead of a part matchedwith the extraction patternpar: The nearest par element ahead of a part matchedwith the extraction pattern from a sentencedate : (1) The nearest date element ahead of a partmatchedt h d with
ith theth extraction
t ti patternttin
i a sentencet(2) The date element which is close to the head ofan article(3) The date when the newspaper article was writtenQuadruplet
Relative Expression
前年比1.4%減(declined 1.4% fromthe previous year)

The Examples which Checking
Components Succeeds
Ex1.
query: パソコン出荷台数(PC shipment volume)
name: パーソナルコンピュータの出荷台数(Personal computer shipment volume)
Ex2.
query: デジタルカメラ出荷台数(Digital camera shipment volume)
name: デジカメの出荷台数(Digital camera shipment volume)
Ex3.
query: 政党支持率(Approval rating for political parties)
name: 支持率
(Approval rating)par: 自民党(LDP)
Ex4.
query: パソコンの出荷台数(shipment volume of PC)
name: 出荷台数
(shipment volume)
par: NECEx5.
query: パソコンの出荷台数(shipment volume of PC)
name: 出荷台数
(shipment volume)
sentence:パソコン出荷金額は前年比1.9%減の1兆7360億円で, 出荷台数は同4.2%増の1249万台となった.
(PC shipment value declined 1.9% fromtheh previousiyear to 1.736
1 736 trillion
illi yenand shipment volume grew 4.2% over
the year to 12.49 million units.)

Experiments

zComplementation Rules

namepar

パソコン出荷数Φ(PC shipment volume)

Relative Expression
dateval
前年比1.4%減
2006年
1326万台(declined 1.4% from(2006) (13.26 million units) the previous year)Implicit Quadruplet Generation¾Applying an explicit quadruplet to the reason rules, other
implicit quadruplet is generated. Evaluation Subject ofT2N Subtask
Explicit Quadruplet
name

par

パソコン出荷数Φ(PC shipment volume)

dateval
2006年
1326万台(2006) (13.26 million units)

Relative Expression
前年比1.4%減(declined 1.4% from the previous year)

Applying explicit elements to the reason rules
date imp = 2006 年 ( 2006 year ) − 1年 (1 year )= 2005 年 ( 2005 year )1326 万台 (13 . 26 million units )1 .4(1 −)100= 1345 万台 (13 . 45 million units )val imp =Implicit Quadruplet
name

par

パソコン出荷数
出荷数

Φ(PC shipment volume)

dateval
2005年年1345万台
3 5万台(2005) (13.45 million units)

Discussion

 Evaluation: We evaluated the following performance: Table 1. T2N Formal Run Evaluation ResultsPrecision Recall F-measurez the performance of our system for the T2N formal run(Table 1)z the performance of our system for relative expression(Table 2)
micro-ave.
0.220
0.029
0.051
z the performance of each module in our system(Table 3)
macro-ave.

0.093

0.021

0.031

 Data set: Mainichi newspaper annotated with XML
Table 2. Evaluation Results for Relative Expressions
tag from 1998 to 2001 (120 articles)
Precision Recall F-measure Query word: 25 statistics names
system1
0.220
0.068
0.108
 Correct data: 314 of the pairs are contained in thesystem2
0.638
0.226
0.333
data set.133 of the pairs for relative expression aresystem1: the system not implementing all functions
system2: the system implementing all functions
contained in the data set.
Table 3. Detailed Evaluation Results of System2
 Output: Our system extracted 30 of the correct pairs.
Precision Recall F-measure Measure: Precision, Recall and F-measuremodule1
1.000
0.669
0.802
module20.718--module30.882

0.455

0.600

module1: Basic element extraction module2: Quadruplet complementation
module3: Component validation

There is remarkable difference between
the micro-average and macro average inprecision in Table 1. The result indicatesthat the system still has uneven
performance.
The result indicates that basic elements
are not sufficiently extracted in Table 2.

module1:
In the topics ``digital camera'' and ``communication device'', the many specific expressions
out of the training data appeared in the data set.
In the topic of ``gasoline'', there is no regularappearance of relative expressions.
expressions
module2:
The failure of the complementing of the dateelement is remarkable in particular. An excessively strict condition for extracting the dateelement caused the failure of the complement.
module3:
Mainly, identification was unsuccessful in thecase where the name element is verbose.