Investigating and extending the methods in automated opinion analysis through improvements in phrase based analysis

Opinion analysis is an area of research which deals with the computational treatment of opinion statement and subjectivity in textual data. Opinion analysis has emerged over the past couple of decades as an active area of research, as it provides solutions to the issues raised by information overload. The problem of information overload has emerged with the advancements in communication technologies which gave rise to an exponential growth in user generated subjective data available online. Opinion analysis has a rich set of applications which are used to enable opportunities for organisations such as tracking user opinions about products, social issues in communities through to engagement in political participation etc.The opinion analysis area shows hyperactivity in recent years and research at different levels of granularity has, and is being undertaken. However it is observed that there are limitations in the state-of-the-art, especially as dealing with the level of granularities on their own does not solve current research issues. Therefore a novel sentence level opinion analysis approach utilising clause and phrase level analysis is proposed. This approach uses linguistic and syntactic analysis of sentences to understand the interdependence of words within sentences, and further uses rule based analysis for phrase level analysis to calculate the opinion at each hierarchical structure of a sentence. The proposed opinion analysis approach requires lexical and contextual resources for implementation. In the context of this Thesis the approach is further presented as part of an extended unifying framework for opinion analysis resulting in the design and construction of a novel corpus. The above contributions to the field (approach, framework and corpus) are evaluated within the Thesis and are found to make improvements on existing limitations in the field, particularly with regards to opinion analysis automation. Further work is required in integrating a mechanism for greater word sense disambiguation and in lexical resource development

Are affective speakers effective speakers? – Exploring the link between the vocal expression of positive emotions and communicative effectiveness

This thesis explores the effect of vocal affect expression on communicative effectiveness. Two studies examined whether positive speaker affect facilitates the encoding and decoding of the message, combining methods from Phonetics and Psychology.This research has been funded through a Faculty Studentship by the University of Stirling and a Fellowship by the German Academic Exchange Service (DAAD)

한국 대학생들의 논증적 에세이에 나타난 절과 구 복잡성의 발달

학위논문(석사) -- 서울대학교대학원 : 사범대학 외국어교육과(영어전공), 2023. 2. 오선영.영어 글쓰기 발달에 관한 연구들은 문법적 복잡성(grammatical complexity)을 학습자의 능숙도를 구별하는 중요한 지표로 인식하고 있다. 초기 연구들은 주로 절 복잡성(clausal complexity)에 기반해 문법적 복잡성을 측정하였지만, 최근 연구들은 구 복잡성(phrasal complexity)에 초점을 두고 있다. 이러한 변화는 절 복잡성이 일상 대화가 가진 특징으로 글쓰기의 초기 발달 단계를 나타내는 반면, 구 복잡성, 특히 명사구의 복잡성은 학문적 글(academic writing)이 가진 복잡성의 전형으로써 높은 수준의 발달 단계를 나타낸다는 인식에 기반하고 있다. 하지만 일부 연구들은 명사구의 복잡성이 글쓰기 능숙도와 큰 관련이 없다는 상반된 결과를 보이고 있는데, 이는 대부분의 연구들이 학습자 모국어가 문법적 복잡성에 미치는 영향을 고려하지 않고 다양한 모국어를 가진 학습자들에 의해 만들어진 코퍼스를 사용했기 때문일 수 있다. 이에 본 연구는 한국인 대학생들이 작성한 글을 분석하여 절과 구의 복잡성이 글쓰기 능숙도와 연관성이 있는지 살펴보고, 그러한 연관성에 크게 기여한 복잡성 특징들을 바탕으로 문법적 복잡성의 발달 패턴을 추정하고자 하였다. 또한 학생들의 글을 질적으로 분석하여, 특정 복잡성 특징을 구현할 때 자주 쓰이는 어휘와 오류 빈도 및 유형을 파악함으로써 능숙도 집단 간의 차이를 더 자세히 묘사하고자 하였다. 본 연구에 사용된 코퍼스는 연세 영어 학습자 코퍼스(Yonsei English Learner Corpus, YELC 2011)에서 추출한 234개의 논증적 에세이로 구성되어 있으며, 이는 CEFR에 기반하여 초급, 중급, 고급의 글쓰기 능숙도를 나타내는 세 개의 하위 코퍼스로 구분되었다. 품사 태깅된 코퍼스를 바탕으로 정규표현식(regular expressions)을 사용하여, Biber et al. (2011)이 제안한 발달단계에 있는 9개의 절 복잡성 특징과 8개의 구 복잡성 특징을 추출하여 각각의 빈도를 계산하였다. 피어슨 카이제곱검정(a Pearson Chi-square test) 결과, 글쓰기 능숙도가 절과 구의 복잡성과 유의한 연관성이 있다는 결론이 도출되었다. 사후검정으로 잔차 분석(a residual analysis)을 수행한 결과, 특히 5개 복잡성 특징이 이러한 연관성에 크게 기여했음이 밝혀졌다. 주목할 만한 발견은 각 능숙도 집단의 주요 복잡성 특징이 Biber et al. (2011)이 제안한 발달단계와 일치하며 따라서 한국인 대학생의 발달 패턴이 두 개의 매개변수, 즉 (1) 구조적 형태와 (2) 통사적 기능에 의해 설명될 수 있다는 점이다. 즉, 한국 대학생들의 문법적 복잡성은 (i) 절의 구성 성분으로 기능하는 정형 종속절(finite dependent clauses functioning as clause constituents)인 부사절의 빈번한 사용에서 (ii) 명사구의 구성 성분으로 기능하는 정형 종속절(finite clause types function as NP constituents)인 WH 관계절에 대한 의존을 거쳐 (iii) 명사구의 구성 성분으로 기능하는 종속구(dependent phrasal structures functioning as noun phrase constituents)인 of 전치사구에 대한 선호로 발달하는 것으로 나타났다. 예상과 달리, 명사의 선수식어(premodifier)로 사용되는 형용사 및 명사의 빈도는 글쓰기 능숙도와 큰 연관성이 없는 것으로 나타났다. 이에 관해 학생들의 글을 질적 분석한 결과, 첫째, 초급 수준의 글은 쓰기 지시문(writing prompts)에 제시된 형용사+명사 조합을 반복적으로 사용하는 경향을 보였다. 둘째, 명사+명사 구조와 관련한 오류가 능숙도가 높아질수록 현저히 낮아지는 경향을 보였다. 마지막으로, 보어절(complement clauses)과 관련해서는 모든 능숙도 수준의 학생들이 매우 한정적인 종류의 통제 명사(controlling nouns)를 사용했으며, 학문적인 글 보다는 일상 대화에서 쓰이는 통제 동사(controlling verbs)를 사용하였다. 이러한 연구 결과는 크게 세가지 교육적 함의를 시사한다. 첫째, 경험적으로 도출된 문법적 복잡성의 발달 단계를 상세한 평가 척도 설명자(rating scale descriptors) 개발과 보다 맞춤화 된 수업 설계를 위해 활용해야 한다. 둘째, 학문적인 글에서 보어절과 함께 자주 사용되는 통제 명사 및 동사에 대한 교실 수업을 통해, 학습자들이 문법적 구조를 학문적인 어휘로 실현할 수 있도록 해야 한다. 마지막으로, 특히 명사를 선수식하는 명사 및 관계대명사절의 사용에 있어 학습자의 글에서 자주 발견되는 오류를 시정함으로써, 문법 구조 사용에 대한 정확성을 향상시켜야 한다.Studies that explore L2 writing development identify grammatical complexity as a primary discriminator for different proficiency levels of L2 writers. In the 1990s, grammatical complexity in L2 writing was often measured by clausal complexity, but the kind of complexity that has recently received particular attention is phrasal complexity. Such a move follows the recognition that clausal complexity represents the complexity of conversation and beginning levels of writing development, whereas phrasal complexity, specifically noun phrase complexity, represents the complexity of academic writing and advanced developmental levels. Some L2 writing studies, however, have yielded conflicting results, showing that phrasal features as noun modifiers have little predictive power for writing quality. One possible reason underlying these inconsistent results might be that most studies in this area have used corpus data from learners of heterogenous L1 backgrounds with no consideration for the significant effect of L1 on the use of complexity features in L2 writing. Thus, this study analyzed essay samples produced only by L1 Korean writers to investigate whether clausal and phrasal complexity is associated with L2 writing proficiency and, if so, what developmental patterns can be observed based on complexity features that contribute substantially to the association. A qualitative analysis of student writing was followed up to provide a detailed description of proficiency-level differences, especially with respect to lexical realizations and error types associated with specific complexity features. The corpus used in the present study contained 234 argumentative essays written by first-year college students, including 78 low-rated essays (A1 and A1+ levels of the CEFR), 78 mid-rated essays (B1 and B1+ levels of the CEFR), and 78 high-rated essays (B2+, C1, and C2 levels of the CEFR). Drawing on Biber et al.s (2011) developmental index, the nine clausal and eight phrasal complexity features were extracted from the tagged corpus using regular expressions to measure the frequency of each feature. The result of a Pearson Chi-square test demonstrated a statistically significant association between the three proficiency levels and the use of clausal and phrasal complexity features. The post-hoc residual analysis revealed five complexity features with great contribution to the association: finite adverbial clause, noun complement clause, WH relative clause, prepositional phrase (of), and prepositional phrase (other). Especially noteworthy is the finding that the main source of complexity at each proficiency level agrees with its corresponding developmental stage reported by Biber et al. (2011), and thus, developmental patterns for Korean college students are successfully explained by two parameters: (1) structural form (finite dependent clauses vs. dependent phrases) and (2) syntactic function (clause constituents vs. noun phrase constituents). Specifically, the development proceeds from (i) clausal complexity mainly via finite adverbial clauses (i.e., finite dependent clauses functioning as clause constituents); through (ii) the intermediate stage of heavy reliance on WH relative clauses (i.e., finite clause types functioning as noun phrase constituents); to finally (iii) phrasal complexity primarily via prepositional phrases (of) (i.e., phrasal structures functioning as noun phrase constituents). Surprisingly, premodifying adjectives and nouns were found to have no significant association with L2 writing proficiency despite being noun-modifying phrasal features. The subsequent qualitative analysis of student writing, however, illustrated greater proficiency of the highly rated essays in using these features in two regards. First, the lower-rated essays drew much more heavily on adjective-noun sequences presented in writing prompts than the higher-rated essays. Second, the number of errors in the composition of noun-noun sequences noticeably decreased in the higher-rated essays. The qualitative observation concerning that-complement clauses, on the other hand, identified the reliance on a limited set of controlling nouns and conversational styles of controlling verbs in student writing across proficiency levels. Three main pedagogical implications are provided based on the findings: (i) the use of empirically derived developmental stages to create detailed rating scale descriptors and provide more customized writing courses on the use of complexity features; (ii) the need for classroom instruction on common academic controlling nouns and verbs used in that complement clauses given the importance of academically oriented lexical realizations of grammatical structures; and (iii) the need to address recurrent errors, particularly in terms of using premodifying nouns and relative clauses.CHAPTER 1. INTRODUCTION 1 1.1 Background of the Study 1 1.2 Purpose of the Study 4 1.3 Research Questions 5 1.4 Organization of the Thesis 6 CHAPTER 2. LITERATURE REVIEW 8 2.1 Grammatical Complexity in L2 Writing 8 2.1.1 Definition of Grammatical Complexity 9 2.1.2 Grammatical Complexity in L2 Writing Studies 13 2.2 Criticism of Traditional Measures of Grammatical Complexity 15 2.2.1 Reductiveness and Redundancy of Length- and Subordination-based Measures 16 2.2.2 Inappropriateness of the T-unit Approach to the Assessment of Writing Development 21 2.3 Measures of Grammatical Complexity in L2 Writing 24 2.3.1 Clausal and Phrasal Complexity in Relation to L2 Writing Development 25 2.3.2 Studies on Clausal and Phrasal Complexity in L2 Writing 31 2.4 Variation in the Use of Grammatical Complexity Features 36 2.4.1 The Effect of L1 Background 37 2.4.2 The Effect of Genre 43 2.4.3 The Effect of Timing Condition 46 CHAPTER 3. METHODOLOGY 50 3.1 Learner Corpus 50 3.1.1 Description of YELC 2011 50 3.1.2 Description of a Subset of YELC 2011 used in the Study 53 3.2 Grammatical Complexity Measures 55 3.3 Corpus Tagging and Automatic Extraction 59 3.4 Data Analysis 65 CHAPTER 4. RESULTS AND DISCUSSION 70 4.1 Descriptive Statistics 70 4.2 The Association between L2 Writing Proficiency and Grammatical Complexity 76 4.3 The Developmental Patterns of Grammatical Complexity 77 4.4 The Grammatical Complexity Features with Great Contribution to the Association 84 4.4.1 Finite Adverbial Clauses 84 4.4.2 Prepositional Phrases as Nominal Postmodifiers 92 4.4.3 WH Relative Clauses 100 4.4.4 Finite Complement Clauses Controlled by Nouns 106 4.5 The Grammatical Complexity Features with Little Contribution to the Association 112 4.5.1 Premodifying Adjectives 113 4.5.2 Nouns as Nominal Premodifiers 120 4.5.3 Finite Complement Clauses Controlled by Verbs or Adjectives 125 CHAPTER 5. CONCLUSION 136 5.1 Major Findings 136 5.2 Pedagogical Implications 139 5.3 Limitations and Prospect for Future Research 142 REFERENCES 145 APPENDICES 161 ABSTRACT IN KOREAN 165석

英語学習者の文処理における意味的・統語的手がかりの利用

筑波大学 (University of Tsukuba)201