Annual Review of Applied Linguistics, 36 (2016), pp. 5–33.
doi: 10.1017/S0267190515000057
In Defense of Tasks and TBLT: Nonissues and Real Issues
Michael H. Long
University of Maryland
abstract
The first aim of this article, addressed in section 1, is to define what is meant, and not meant, by task and task-based language teaching (TBLT). The second is to summarize and evaluate 14 criticisms that have been made of both. Section 2 responds to five alleged problems with TBLT’s psycholinguistic rationale, section 3 to six at the classroom level, and section 4 to three claimed problems with implementing TBLT in specific contexts. A few of the criticisms touch on important matters, but most, I will suggest, are nonissues. The third aim of the article is to identify some genuine problems in need of resolution—real issues—and briefly to illustrate research programs under way to address them.
TBLTとは何であり、何でないか。
TBLTへの14の批判（心理言語学的観点５、教室的観点３、実行的観点３）
TBLTの真の問題とその対処について言及。
今回は、TBLTへの心理言語学的観点からの批判の一つについて。
2.1. Research Findings on Interlanguage Development and Teachability Are Insufficient to Discredit the Grammatical Syllabus and PPP
学習者の中間言語発達と教授可能性についての研究結果は、文法シラバスやPPP（Presentation-Practice-Production）を却下するのには不十分である。
このTBLT批判（文法シラバス・PPP擁護論）に対して、Long(2016)は以下のように述べている。
Contrary to what defenders of the structural syllabus and PPP—like Bruton (2002a, 2002b), Widdowson (2003, pp. 111–133), and Swan (2005)—and most commercial textbook writers assume, and as is only to be expected if developmental sequences are real, 40 years of instructed SLA (ISLA) research and classroom studies have demonstrated that teachers cannot teach whatever they want, whenever they want, if language learning is their goal. Stages in sequences cannot be skipped by presenting learners with full target-like grammatical structures and drilling them until they are “automatized.” In Pienemann’s terms, processability determines learnability, and learnability determines teachability (Pienemann, 1984). Students play a decisive role in the language-learning process; their readiness to learn is not determined by the day of the week or the page in a textbook. As Skehan (2002, p. 294) noted, PPP and the skill- builders’ view is that language acquisition is teacher-driven, whereas, with support from decades of SLA research, TBLT views language acquisition as learner-driven. （Long, 2016, p.9）
40年にわたるSLS研究を通じて、発達段階（developmental sequences）・習得順序（acquisition order）が想定され、教師が教えたいときに教えたい内容を教えても習得されないということが実証されてきた。Pienemann流に言えば、processability（情報処理可能性）がlearnability（学習可能性）を決め、learnabilityがteachability（教授可能性）を決める。これを踏まえているのがTBLTである。言語獲得をスキル習得と捉える立場がteacher-drivenであるのに対して、TBLTはlearner-drivenなのである、と。
この点、Long（2016）が主張する、以下の言語教育における10の方法論的原則（Methodological Principles）のMP8と関連する。
MP1: Use task, not text, as the unit of analysis MP2: Promote learning by doing
MP3: Elaborate input
MP4: Provide rich input
MP5: Encourage inductive “chunk” learning
MP6: Focus on form
MP7: Provide negative feedback
MP8: Respect learner syllabi and developmental processes
MP9: Promote cooperative collaborative learning
MP10: Individualize instruction
(Long, 2016, p.7)
MP8で、learner syllabiやdevelopmental processesというと、テクニカルでわかりにくいが、要するに、教師が教える順序に沿って学習者が学ぶわけではない。学習者のreadinessの問題があるという趣旨で捉えられる。teacher-drivenよりleaner-drivenとは、teachingという行為も言ってみればlearningの支援活動と考えれば納得せざるを得ない主張であると言えよう。
Klapper(2003)らの折衷的立場（TSLT）と純粋なTBLTとの差異に関しては、Long(2016)は以下のように述べている。
The difference, however, and it is a major difference, is that there is no assumption in genuine TBLT that performance of individual grammatical structures can be developed to native-like levels rooted in a separate explicit knowledge system via the massive practice required for automatization, or that if accomplished, the new underlying knowledge will morph into the separate implicit system. In other words, not just the methodology but the underlying psycholinguistic rationale for TBLT is quite different. Klapper’s (2003) proposal, like that of R. Ellis (1994, 2003, 2009), is for a hybrid model, one that may yet turn out to be correct but that some would see as fatally flawed because it seeks to meld two oppositional psycholinguistic positions. In my view, if there is a place for skill acquisition theory in TBLT, it is for the use of task repetition to improve task performance, not performance of individual grammatical structures before their time. (Long, 2016, p.11)
TBLTでは、明示的な知識体系が多くの自動化訓練を経てネイティブのようになるとか、あるいは上手く行けば新たな知識がやがて別個にある暗示的体系の中に形を変えてとりこまれるなどと想定しない。その種の相容れない想定を含む点で、Klapper(2003) やEllis(1994, 2003, 2009)の折衷論は治し難い欠陥があるのだと。
スキル習得論理論については、Dekeyser（1998）も引用して批判している。
it is safe to assume ... that none received instruction along the lines of what skill acquisition theory would seem to imply: explicit teaching of grammar, followed by FonF [focus on form] activities to develop declarative knowledge, and then gradually less focused communicative exercises to foster proceduralization and automatization. (DeKeyser, 1998, p. 58)
「宣言的知識の発達を促すフォーカスオンフォーム」というくだり、一瞬、目を疑う。このFocus on Formに対する認識はLongのそれとズレているのではないか。それはそれとして、ここで言わんとしているのは、明示的文法指導から始めて、エクササイズについては言語形式の制約の強い訓練から徐々にその制約をゆるめていくことで、宣言的知識を手続き的知識に自動化する、そういうスキル習得理論が描くようなプロセスで教わった人はいないだろうということ。
ただし、explicit vs. implicitについて、両者のインタフェイスをどの程度認めるかは異なる立場が認められるイシューである。仮に、explicitな知識がimplicitになることなどあり得ないとするならば、折衷案を認めない純粋なTBLTを志向するというLongの立場が理解されることになる。しかし、その前提が変われば、TBLTに対する姿勢にも影響を与えることになるはずである。
Swan (2005)への舌鋒鋭い反論。Nunan (1991)も引いて、TBLT擁護にあてている。
Having discounted decades of empirical findings, Swan reassured readers that “traditional structure grading is informed by pedagogic experience and expertise” (Swan, 2005, p. 394). Their source is unspecified. In fact, he repeatedly settled arguments to his satisfaction by appeals to what is “sensible” (to whom is left unstated), to “experience,” which differs from one individual to the next, and to “common sense,” which would obviate the need for debate if it really were common. Such an attitude to research is distressingly common among TBLT’s loudest critics, who frequently demand more studies, while offering none of their own. More than 25 years ago, Nunan was able to write:
One of the strengths of task-based language teaching is that the conceptual basis is supported by a strong empirical tradition. This distinguishes it from most methods and approaches to pedagogy, which are relatively data-free.” (Nunan, 1991, p. 283)
Swan(2005)などは、数十年にわたる実証研究の成果を否定し、「経験」と「常識」により支持される伝統的な構造シラバスを推奨する。経験は個人によって異なり、常識で判断できるならこの種の論争など不要であるにもかかわらず。TBLTをや喧しく批判する者にはこの手合いが多い。相手に研究成果を要求しながら自らはそれをまったく示さない。四半世紀以上も前に、Nunan(1991)がすでに、TBLTほど強固な実証研究に支えられた方法はない、他の教育メソッドやアプローチは、みな相対的にデータを考慮しないと指摘していた、と。
以下、この論点の結び。経験は研究を動機づけるが、研究にとってかわるわけにはいかないという指摘は首肯するほかない。
Twenty-five years later, the research basis for TBLT is many, many times greater. As an experienced classroom teacher and teacher educator myself (and one, incidentally, who learned a great deal working closely with Michael Swan early in my teaching career), I am certainly aware of, and open to, the insights that come from practice. However, classroom experiences vary across individuals and contexts and over time, and are usually subjective and impressionistic. They can motivate research, but are no substitute.
Longが教師時代にSwanと共に仕事をしていたというくだり。後の両者の主張を考えると皮肉である。
（SATO)