Explicit L2 grammar instruction leads to larger learning effects than implicit instruction, as reported in the reviewed synthesis literature¶

Claim · All claims
Evidence · 4 studies · 3 quant-synthesis r2, 1 review r2 · q2–q3
Currency · newest study 2022 · 3 of 4 entries checked against their sources (automated) · not reviewed by a person

Subclaims¶

q2 i? Instruction incorporating explicit techniques leads to more substantial effects than implicit instruction in L2 learning. → Aydinbek C 2022 q3 i? A research synthesis and meta-analysis of 49 experimental and quasi-experimental L2 instruction studies published 1980–1998 found explicit types of instruction more effective than implicit types; the abstract prints no effect size. → Norris & Ortega 2000 q3 i? A meta-analytic update of Norris and Ortega (2000), pooling 34 studies that directly compared explicit and implicit instructional treatments (11 from the original and 23 published 1999–2011), found explicit instruction more effective overall; the abstract prints no effect size. → Goo et al. 2015 q3 i? A meta-analysis of 41 studies of English grammatical features found larger effect sizes for explicit than implicit instruction for both simple and complex features; the abstract prints no effect size. → Spada & Tomita 2010

Evidence¶

Aydinbek C 2022¶

Aydinbek C. (2022). Contributions of cognitive theory to the problem of automatization of grammatical structures in teaching foreign language. Educational Research and Reviews. https://doi.org/10.5897/ERR2022.4230

q2 · i? · review · r2

The review reports, citing Norris and Ortega (2000), this meta-analytic finding on explicit versus implicit L2 instruction; the review narrates the result rather than computing it, and no effect size is printed here.

"on average, instruction that incorporates explicit (including deductive and inductive) techniques leads to more substantial effects than implicit instruction"

Norris & Ortega 2000¶

Norris, J. M., & Ortega, L. (2000). Effectiveness of L2 instruction: A research synthesis and quantitative meta-analysis. Language Learning, 50(3), 417–528. doi:10.1111/0023-8333.00136

q3 · research synthesis and meta-analysis (abstract only) · i? · n=49 studies · quant-synthesis · r2

Systematic research synthesis and meta-analysis of experimental and quasi-experimental studies of L2 instruction published between 1980 and 1998, comparing average effect sizes from 49 unique sample studies. The abstract reports that focused L2 instruction produces large target-oriented gains, that explicit types of instruction are more effective than implicit types, and that the effects are durable. Only the abstract was read: it prints no effect size, confidence interval or participant count, so the size of the explicit advantage is not established here, and the authors state that generalizability is limited because the field had not yet rigorously operationalized its type-of-instruction constructs. The Aydinbek (2022) entry above reports this same finding second-hand, so the two entries are not independent evidence.

"explicit types of instruction are more effective than implicit types"

Goo et al. 2015¶

Goo, J., Granena, G., Yilmaz, Y., & Novella, M. (2015). Implicit and explicit instruction in L2 learning: Norris & Ortega (2000) revisited and updated. In Implicit and Explicit Learning of Languages (Studies in Bilingualism, pp. 443–482). John Benjamins Publishing Company. doi:10.1075/sibil.48.18goo

q3 · meta-analysis (abstract only) · i? · n=34 studies · quant-synthesis · r?

Meta-analytic review restricted to studies in which explicit and implicit instructional treatments were compared directly: 34 unique sample studies, 11 taken from Norris and Ortega's (2000) meta-analysis and 23 new studies published between 1999 and 2011. Overall, explicit instruction was more effective than implicit instruction, and moderator variables were also analysed. Only the abstract was read: it prints no effect size, no moderator results and no participant count. Because 11 of its 34 studies are Norris and Ortega's, this entry and theirs are partly the same evidence.

"Overall, explicit instruction was found to have been more effective than implicit instruction."

Spada & Tomita 2010¶

Spada, N., & Tomita, Y. (2010). Interactions between type of instruction and type of language feature: A meta-analysis. Language Learning, 60(2), 263–308. doi:10.1111/j.1467-9922.2010.00562.x

q3 · meta-analysis (abstract only) · i? · n=41 studies · quant-synthesis · r?

Meta-analysis of 41 studies of explicit and implicit instruction on the acquisition of simple and complex grammatical features in English, with features classed as simple or complex by the number of criteria applied to arrive at the correct form (Hulstijn & de Graaff, 1994) and treatments classed as explicit or implicit following Norris and Ortega (2000). Effect sizes were larger for explicit than implicit instruction for both simple and complex features, and explicit instruction contributed to both controlled knowledge and spontaneous use. Only the abstract was read: it prints no effect sizes or participant counts, and the target language in every study was English.

"The results indicate larger effect sizes for explicit over implicit instruction for simple and complex features."

Studies bearing on this claim¶

In second-language grammar, does explicit instruction about a form help more than leaving it to implicit exposure? This table gathers the studies behind this claim and the 23 narrower claims that bear on it: 19 distinct studies (6 review, 5 causal, 4 quant-synthesis, 4 theoretical), q1–q3, 0 of 19 with an effect size coded. One row per study, codes as each entry records them; no effect is averaged and no verdict is drawn. Built by scripts/synthesize_claim.py from eval/synthesis/; a row that looks wrong is fixed on the claim it comes from.

Discussion¶

Learner Variables¶

• Syntax — outcome: instruction changes it

Related Claims¶

• Review synthesis: explicit teaching matters, but its advantage over other approaches varies by context and structure — a broader claim this one bears on
• Explicit grammar teaching outperforms implicit teaching; one review found the advantage only for complex rules, but a meta-analysis found it for simple rules too — related
• High-explicitness rule-oriented instruction outperforms implicit instruction or no instruction — a narrower finding that bears on this claim
• Explicit teaching is more effective for EFL copular be learning but its effect is not durable — related
• A 1982 bilingual-education teacher-training packet asserts, citing Krashen, that repetitive drill and grammar-focused instruction are ineffective for second language acquisition — reports the opposite
• A 2017 cyberlearning community report states that students learn more from games when bridging activities connect game learning to classroom instruction, and that learning analytics can strengthen the connection — related
• Form-focused instruction can contribute to the acquisition of second language implicit knowledge, as shown in studies measuring learners' free production — related
• Implicit learners do not outperform other learners on complex second language rules — reports the opposite
• Instructed learners outperform all other condition groups in learning simple second language rules — a narrower finding that bears on this claim
• Attention to form via structural analysis or via highlighting structures in context promotes interlanguage grammar acquisition, but only highlighting in context comes with comprehension of input — a narrower finding that bears on this claim
• Learners acquired untaught syntactic properties but failed to show sensitivity to agreement they had been explicitly taught and practiced — related
• The study tested the interaction of explicit instruction with complexity and morphology/syntax across four L2 structures — a narrower finding that bears on this claim
• Learners receiving both form- and meaning-focused instruction improved more than a form-focused group (attributed to Park, 2000) — related
• Explicit instruction facilitates the acquisition of L2 grammar — related
• Mental representation is not amenable to direct explicit instruction because UG and parsers operate only on input data — reports the opposite
• Unpressured within-task planning improves accuracy only when attention is guided to form — related
• Upper-intermediate EFL learners taught with proactive FOF scored significantly higher on a grammar posttest than learners taught with reactive FOF — related
• The success of form-focused instruction in building implicit knowledge depends on the choice of target structure and the extent of the instruction — related
• Explicit correction did not produce evidence of learned morphological generalizations to novel stimuli in adult L2 learners — a narrower finding that bears on this claim
• FFI involving extensive instruction directed at simple structures was more likely to succeed in developing implicit knowledge — related
• A 1999 conference paper reports, citing Ellis and LaPorte (1997), that instruction has little or no effect on the route of L2 acquisition — reports the opposite
• Explicit teaching of grammar rules enhances their learning, and rules are learned faster and better when repeated in communicative tasks — a narrower finding that bears on this claim
• Explicit strategy instruction, unlike implicit strategy instruction, is associated with a gain in student performance — related
• Explicit teaching does not improve overall quality of written causal explanations but improves use of second-order language and causal connections — related