日本大学生産工学部　研究報告B（文系）第51巻

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─ 27 ─１．はじめに本研究の目的は，教育用例文コーパスSentence Corpus of Remedial English（SCoRE）に収録されている英文について，学習者による英文難易度評価の観点から，他のコーパスと比較してSCoREがDDLを行う上でどの程度，教育用コーパスとして適切なのかを客観的に評価することである。コーパス言語学や自然言語処理の技術を英語教育に応用するデータ駆動型学習（data-driven learning: DDL）は，英語学習者がコーパスから検索ツールを使ってターゲット語を検索し，豊富な言語使用例を見てことばの規則を発見して学んでいく教授法である（Aston, 2001；Johns, 1997；Hunston, 2002）１），２），３）。そのため，英語授業にDDLを取り入れるには，学習者にとって適切なレベルの教育用コーパスが必要となる（Flowerdew, 2012）４）。日本人英語学習者の多くはCommon 研究ノート日本大学生産工学部研究報告Ｂ2018　年　６　月　第　51　巻英語初級者向け教育用例文コーパスSCoREの英文難易度評価中條清美＊，濱田　彰＊＊，小林雄一郎＊＊，ジョンソン・ミシェル＊＊Evaluating the Diculty Level of SCoRE Sentences for Low Prociency EFL LearnersKiyomi CHUJO＊，Akira HAMADA＊＊，Yuichiro KOBAYASHI＊＊ and Michelle JOHNSON＊＊＊Since its inception in 2012, the Sentence Corpus of Remedial English (SCoRE) project is now at the end of the fourth phase of development. It currently contains 22 categorized grammar items with 10,459 level-specic, semi-authentic sentences (101,521 words) written to satisfy pedagogical considerations such as appropriateness, usability, and fair use for copyright issues. Since most Japanese learners of English are at the CEFR A1 or A2 levels, SCoRE was created for teachers and low prociency Japanese EFL learners. The purpose of this study was to evaluate SCoRE for its “appropriateness” as an educational corpus. CEFR A2 level university students (N = 29) rated the appropriateness of 36 concordance lines extracted from four different corpora, SCoRE, CoBLE, WebParaNews, and the BNC. Ratings were based on seven factors: sentence difculty, length, structure, meaning, authenticity, vocabulary level, and Japanese translation availability. The results of random forest modeling showed that the three most important factors affecting the appropriateness of sentences for data-driven grammar learning were sentence structure, sentence meaning, and having Japanese translations. Descriptive statistics indicated that SCoRE, a parallel English and Japanese corpus, received the highest evaluations in terms of understandability of concordance lines. These ndings suggest that SCoRE is appropriate for the target audience of developmental L2 English learners.Keywords:Educational Bilingual Corpus, Data-Driven Learning, Corpus Evaluation, Grammar Teaching, Appropriateness　＊日本大学生産工学部教養・基礎科学系教授＊＊日本大学生産工学部教養・基礎科学系助教