National Institute of Informatics

Kiyoko Uchiyama

1

A Study for Introductory Terms in Logical Structure of Scientific P

apers

Outline

1. Purpose, background, motivation

2. What’s “Introductory terms”

3. Analysis of logical structure

4. Analysis of structural role

5. Apply to MIC theory

6. Future works

2

Author-based logging in

Result of author’s publications &similar papers and similar research

ers

Keyword-based logging in

Result of keyword search by cosine similarity

Select seed paper & several viewpoints

Jump to Cinii & REO

Purpose

9

• Investigate the occurrence of introductory terms in logical structure of textbooks, research papers and encyclopedia

• Categorize each sentence including introductory terms into structural roles

• Analyze how to behave the introductory terms in Introduction section

Background

• A lot of technical terms exit in specific domain

• Difficult to identify the most important terms in the target field for novices

• Novices should learn the basic and necessary terms in the field in the first priority

10

Our motivation

• Apply to a method for advanced search

• Assume that introductory terms ..

– play a important role for describing domain knowledge

– help novices to understand the content of academic papers

11

What is “introductory terms”?

12

• Essential & basic terms for a target field

• The terms that should make it a first priority to learn in a target field

• Difficult to understand more difficult terms in the target field without the introductory terms

novice

Hidden Markov Model

•Chasen

•MeCab

•JUMAN

•KAKASI

Paper Ａ

Conditional Random field

Maximum entropy model

High 　　→→　 introductory degree 　→→ low

•Morphological analysis▼

•Syntactic analysis

•Semantic analysis

Tutorial paper

PaperB

PaperC

Automatic definition

14

• Define the introductory terms which are selected in common by a lot of experts

• Experts of specific field wrote/edited the following resources

– Textbooks

– Encyclopedia

– Research papers

Priority ( Frequency )

15

• Authors arrange the contents of their textbooks in an easy-to-understand order

• Authors include important keywords in title, author-assigned keywords in academic papers

• The table of contents of Encyclopedia is edited by a lot of experts

Logical Structure

17

• Distribution patterns in IMRD structure (Introduction, Method, Result and Discussion) of the text might be informative for identifying the introductory terms

• Assume that introductory terms are frequently used in introduction section

Data set

18

Target field: NLP, Target language: Japanese

• Textbooks: 39 textbooks whose titles included “natural language processing”

• Natural Language Processing Encyclopedia written in Japanese

• Academic papers: 1421 papers of NLP research group in Information Processing Society of Japan from 1993 to 2007

Data collection

19

• Morphological analysis by MeCab for Japanese

• Extract sequential noun strings as the term candidate in

– the textbooks(694 types)

– table of contents of Encyclopedia(463 types)

– title, abstract and author-assigned keywords in papers ( 13493 types)

• 90 terms appeared in all of three resources

Analysis of Logical Structure

20

• Use full text of research papers in NLP field

• Target papers which describe experiments and results

• Extract 100 papers which include words such as “experiment”, “evaluation”, “precision” and “%” and so on

• Divide full texts into 6 sections

21

　numbers

of sentence

s

numbers of sentences including

introductory terms

rate

Abstract 656 362 0.552Introduction 2448 1284 0.525

Experiment 8931 2701 0.302Related works 1222 542 0.444

Conclusion 805 394 0.489Others 11965 3439 0.287Total 26027 8722 0.376

Analysis of structural role

• Extract sentences including introductory terms in Introduction

• “Introduction” section has several kinds of sentences outlining the research

• Categorize each sentences into structural role by manual

• Analyze the sentence from the viewpoint of various features

22

Structural role

23

1. Hypothesis

2. Motivation

Problem

3. Background

4. Goal

5. Object

6. Method( new-old )

7. Experiment

8. Model

9. Observation

10. Result

11. Conclusion

Base on the the CoreSC Annotation scheme( Soldatova & Liakata, 2007)

Features in structural role

• Tense, aspect, modality

• Verbs

• Syntactic features

• Lexical features

24

Tense, Aspect

25

• Background– Recently, morphological analysis has been transiti

oning from the method based on heuristic knowledge to the method using probabilistic model. ( 近年、　〜しつつある。）

• Related Works

– The authors is proposing/proposed a method for morphological analysis using rule-based paraphrasing 　（提案している => 提案した）

Modality, Verbs

• Modality

– The high level of language processing would be needed for assigning semantic features to words

• 必要かもしれない

• Verbs

– Specific verbs in present sense tend to be used in Object

Ex. Propose 、 intend, design, tackle26

Syntactic features

28

• Temporal expression (Background)

– Recently 　近年、 so far 　これまで、

– Several researches have been done …. 　• 研究が行われてきた

• Fixed expression (Motivation, Related-works)

– It is inevitable/necessary 　〜必要である

– The research has not be done … 　　〜の研究は行われていない

– [Authors] is proposing … 　提案している

Lexical features

• Keywords related to structural role

– Problem

• One of the main problems is that unknown word and new terms have been increasing day by day.

• it costs a lot of time …

– Experiment

• We conducted/ proceeded the experiment

• In order to evaluate our proposed method,

– Result

• We show the result of the experiment …

• We could obtain better precision …

29

Discussion

• Introductory terms are frequently used in sentences to position the proposed method in a target field

• Introductory terms and the structural role introduced the basic domain knowledge which is necessary for understanding the main purpose of papers

• Possible to classify each sentence into specific structural role automatically

30

Future works

31

• Categorize sentences including introductory terms into each structural role automatically

• Analyze the collocation words with introductory terms

– Syntactic information ( subject, object, modifier, and so on )

– Semantic relation between the introductory terms and other terms ( objective, method, target )

Information types

32

contents information Components of papersSemantic information

Intensive expression

Logical structure

Informative expression

Structural role

Syntactic information

Basic expression Tense, aspect, modalityIntroductory terms, author assigned keywords

Apply to MIC theory

• Logical structure consists of structural roles

• The authors consider the discourse of their paper based on their proposed model/method

• MIC theory could be applied to sentence level and discourse level

• The order strategy of structural roles might relate to meta-information

33

Analysis of Hierarchy

Sentence level

– There are no researches for [METHOD]

Basic expression → 　 informative expression

Discourse level

• Background: Recently, [METHOD]has been used in…

• Motivation: We need to consider [METHOD] for morphological analysis

• Objective-New: We propose [METHOD] 　← Focus34

Conclusion

• Might be interested in analysis of introductory terms and their surrounding syntactic and semantic information from the view point of MIC ( I’m not sure…)

• The result of the analysis would hope to contribute the understanding of academic papers

35