Effectiveness of explicit vs. implicit L2 instruction

In Applied Linguistics, a debate has been going about what the more effective teaching method is: explicit instruction, which focuses on communicative skills with explicit explanation of linguistic rules, or implicit instruction, which focuses on communicative skills with lots of frequent, authentic input with no focus on rules (Long, 1991; Ellis, 1995 ; Van Patten, 2002 ; Verspoor & Winitz, 1997). In their meta-analysis, Norris and Ortega (2000) show that even though results suggest that explicit instruction is more effective, this outcome may be due to how effectiveness was measured. The current project aims at answering the question: Is explicit or implicit L2 instruction better? Using a meta-analysis approach , I aim at reflecting first on the definition of the term effectiveness and then on the best measures for explicit and implicit L2 instruction. The insights obtained from the meta analyses will be applied to longitudinal free-production data (already collected) in two conditions: explicit and implicit instruction. The results should not only give a clearer idea in the field of L2 teaching about what type of instruction may be most effective for the groups studied but also provide useful ways to measure effectiveness.