**Updated 4.27.2022**
with Polio (2012)

A LOT of this research has been shared by Eric Herman, either in the Acquisition Classroom Memos, his book, “Research Talks…,”or from my direct requests. Thanks, dude! As you’ll see, there is very little support (none?) for explicit grammar, or traditional rule-based language instruction. Even effectiveness aside, it should be clear that the practice has no place in inclusive K-12 classrooms (and probably beyond), since affective factors—alone—are shown to result in enough negative consequences. N.B. The highly-motivated independent adult learner can, and probably will do anything they want, and/or feel is helping them regardless of any proof. K-12 students are NOT those people.

Dlaska, A., & Krekeler, C. (2017). Does grading undermine feedback? The influence of grades on the effectiveness of corrective feedback on L2 writing. The Language Learning Journal, 45(2), 185-201.

• Three groups wrote essays. Two of the groups got corrective feedback, and one group didn’t. One of the corrective feedback groups was also graded. The following week, students revised essays. Both corrective feedback groups showed significant improvements in accuracy, but getting a grade made no difference. The other group made no gains in accuracy.
• However, when all three groups wrote a new essay on a new topic after three weeks, researchers found no difference in accuracy among the three groups, regardless of grading or corrective feedback.

Doughty, C.J. (2004). Effects of instruction on learning a second language: A critique of instructed SLA research. In: B. VanPatten, J. Williams, S. Rott, & M. Overstreet (Ed.), Form-meaning connections in second language Acquisition (pp. 181-202). Mahwah, NJ: Lawrence Erlbaum Associates.

• “Whereas the early instructed SLA did not operationalize the instructional treatment in any way, the current state of affairs is that L2 instruction is typically designed and measured in ways that are not pscyholinguistically valid. In other words, processing in which learners typically engage in instructed SLA research to date is not of the kind relevant to SLA processes” (p. 193).
• “In sum, the case for explicit instruction has been overstated. In addition, given that only 30% of studies have employed implicit pedagogic techniques, and that outcome measures have been severely biased toward constrained construction, language manipulation, and the assessment of declarative knowledge (90% of measures), any advantages for implicit instruction have likely been understated. In other words, under the present biased research conditions, any observed effects of implicit instruction are remarkable indeed! (Doughty, 2004, p. 199).

Kepner, C. G. (1991), An Experiment in the Relationship of Types of Written Feedback to the Development of Second‐Language Writing Skills. The Modern Language Journal, 75: 305-313. doi:10.1111/j.1540-4781.1991.tb05359.x

• “In this study, error-corrections and rule-reminders seemed to serve neither for significantly improving students’ level of written accuracy in L2 surface skills nor for enhancing the ideational quality of L2 students’ writing” (p. 310).
• Results:
  Higher-level thinking ideas:
  – Meaning-based feedback group wrote more
  – High verbal ability subjects wrote more
  Accuracy:
  – No statistical differences. In other words, a group that does not get errors corrected is just as accurate. And accuracy also does not depend on level of verbal ability (stated another way: an A student made the same number of language errors as a C student).

Morgan-Short K, Finger I, Grey S, Ullman MT (2012) Second Language Processing Shows Increased Native-Like Neural Responses after Months of No Exposure. PLOS ONE 7(3): e32974. https://doi.org/10.1371/journal.pone.0032974

• “Thus overall, the evidence indeed seems to suggest that although explicit training can provide fast early grammar learning, it might slow the attainment of native-like grammatical processing and possibly native-like proficiency as well. . . If the learner’s goal is rapid learning rather than the eventual attainment of high proficiency, explicit training might do the trick. But if native-like attainment is desired, explicit training might be harmful, and it might be better to stick solely or largely with more implicit training approaches” (p.15).
• 1. Early test: implicit group not relying on rule-based processing, but item-based
  2. Short-term test: only the implicit group had L1-like neural activity
  3. Long-term test: both groups had L1-like neural activity, but more for implicit

Norris, J. M. and Ortega, L. (2000), Effectiveness of L2 Instruction: A Research Synthesis and Quantitative Meta‐analysis. Language Learning, 50: 417-528. doi:10.1111/0023-8333.00136

• This meta-analysis is often cited as support for rule-based instruction, yet has significant limitations in terms of bias towards explicit learning seen all throughout the field of SLA:
  1. Hawthorne-like effect: the treatment makes subjects aware of the name of the game, so they know where to focus their attention during the testing.
  2. There are more explicit learning treatment studies.
  3. Poorly designed or nonexistent comparison group.
  4. The tests often favor explicit learning.
  5. The results are usually tested only in the short-term.
• “Thus, in the current domain, over 90% of the dependent variables required the application of L2 rules in highly focused and discrete ways, while only around 10% of the dependent variables required relatively free productive use of the L2. In addition, most primary research has operationalized implicit treatments in relatively restricted ways, whereas explicit treatments often involve combinations of several instructional components” (p. 483).

Polio, C. (2012). The relevance of second language acquisition theory to the written error correction debate. Journal of Second Language Writing, 21(4), 375-89. https://doi.org/10.1016/j.jslw.2012.09.004

• “We have not sorted out what explicit knowledge students can and cannot apply, and all teachers know that students do not apply all of their explicit knowledge when writing or editing (p. 386).

Rothman, J. (2008). Aspect selection in adult L2 Spanish and the Competing Systems Hypothesis: When pedagogical and linguistic rules conflict. Languages in Contrast, 8(1), 74-106.

• Highly advanced Spanish L2 speakers who took 5 years of courses and were also teachers of the language misused common verb forms. This was attributed to inaccurate textbook rule generalizations. Other highly advanced L2 speakers with no classroom experience were more native-like.
• “Not one naturalistic learner demonstrated the observed pattern of target-deviancy that the majority of tutored learners did.”
• Although it makes sense that textbook rules might benefit an advanced speaker, allowing them to adjust their output, this is another study showing how textbook linguistic knowledge can actually impede native-like use of language.

Semke, H. D. (1984), Effects of the Red Pen. Foreign Language Annals, 17: 195-202. doi:10.1111/j.1944-9720.1984.tb01727.x

• “Corrections do not increase writing accuracy, writing fluency, or general language proficiency, and they may have a negative effect on student attitudes, especially when students must make corrections by themselves” (p. 195).
• “Instead of enduring the drudgery of finding and marking errors, the teacher can, with a clear conscience, enjoy becoming better acquainted with students through mutual sharing of information” (p. 202).
• “Responding to the students’ writing as in treatment 1 (with reinforcing responses and questions in the target language, so that students know that they are being understood) results in a student-teacher communication which could play a vital role in building a positive relationship” (p. 202).

Truscott, J. (1996), The Case Against Grammar Correction in L2 Writing Classes. Language Learning, 46: 327-369. doi:10.1111/j.1467-1770.1996.tb01238.x

• “In related work, follow-up testing and observation showed that knowledge which students had apparently acquired actually disappeared in a matter of months, probably indicating that the teaching had produced nothing more than pseudolearning (Harley, 1989; Lightbown, 1983, 1985, 1987; Lightbown, Spada, & Wallace, 1980; Pienemann, 1989; Weinert, 1987; White, 1991)” (p. 346-347).
• “The L2 evidence fits very well with that from the L1 studies; correction is clearly ineffective” (p. 330).
• “Teaching practices that rely on transfer of knowledge, without any concern for the processes underlying the development of the language system, are not promising. Grammar correction, as almost universally practiced, does exactly that” (p. 343).
• “In other words, teachers can help students’ accuracy at least as much by doing nothing as by correcting their grammar; and by doing nothing teachers can avoid the harmful effects discussed above. So the alternative to correcting grammar is straightforward: Do not correct grammar” (p. 361).
• Truscott calls the assumption that “students want to be corrected” the “most interesting and most disturbing argument” (p. 359). The responsibility of teachers is to help students learn, not do what students think is best. Truscott (1999) says giving students what they want only further reinforces the false belief. Instead, teachers should educate. Truscott acknowledges this can be a challenge. But studies do show students not receiving grammar correction learn more and have better attitudes.

White, L. (1991). Adverb placement in second language acquisition: Some effects of positive and negative evidence in the classroom. Second Language Research, 7, 133-161. Retrieved from http://www.jstor.org/stable/43104427

• The subjects were native French speakers learning English. In French, “John eats always the pie” is grammatical, so the learners accepted such English sentences as grammatical.
• One group of learners was given negative feedback and explicit instruction on adverb placement. They made short-term gains (which is what we might see if quizzing/testing units based on a textbook grammar syllabus).
• However, the group also overgeneralized their knowledge, essentially “learning” that the pattern Subject-Verb-Adverb is ungrammatical, which means they then thought “John walks slowly to school” was also ungrammatical.
• 1 year later, White retested the very same group and found they were back to square one, as if the instruction never happened, again accepting English sentences like “John eats always the pie” as grammatical.