A Review of McLean’s Evidence for the Adoption of the Flemma as an Appropriate Word Counting Unit

本稿は，第二言語（L2）語彙研究の分野における重要なギャップ，すなわち第二言語（L2）学習者が単語の屈折形や派生形を理解する能力を扱ったMcLean（2018）の論文を検証するものである。彼の研究において，McLean は，ワードファミリーを適切なカウント単位として用いるべきとする研究に於ける結論に疑問を投げかけている。日本人EFL 学習者（N=279）を3 つの習熟度グループ（初級，中級，上級）に分け，屈折形と派生形の知識を英日翻訳テストにより測定した。その結果，全レベルの学習者において，12単語について，基本形，屈折形，派生形を理解する能力に差があることがわかった。McLean は，単語の基本形と関連する屈折形であるフレマが，ワードファミリーよりも適切な単語カウント単位であると結論付けている。 本稿では，まず主要な用語と概念について説明し，次にMcLean の論文の概要を述べる。その後，McLean の主張の妥当性を検証し，L2 語彙研究分野での重要性を評価するために，この研究の長所と短所を評価した上で，この論文の批評を行う。最後に，L2教室における形態論の扱いを含む，この研究の教育的示唆について考察する。

This review article examines a paper by McLean (2018) in which he addresses an important gap in the field of second language (L2) vocabulary research: the ability of L2 learners to understand the inflected and derived forms of words. In his study, McLean questions the inferences made in research that uses the word family as an appropriate unit of counting. Japanese EFL learners (N=279) were divided into three proficiency groups (beginner, intermediate, and advanced), and their knowledge of inflectional and derivational forms was measured using an English to Japanese translation test. It was found that learners at all levels differed in their ability to understand the base form, inflected forms, and derived forms of 12 words. McLean concludes that the flemma, a word’s base form and associated inflectional forms, is therefore a more appropriate word counting unit than the word family. Our review begins with an explanation of the key terms and concepts in this field of research, followed by an overview of McLean’s paper. A critique of the paper follows in which we examine the validity of McLean’s argument, and evaluate the strengths and weaknesses of the study with a view to assessing its importance in the L2 vocabulary research field. We close with a consideration of the pedagogical implications of the study, including the treatment of morphology in the L2 classroom.