An Empirical Study On The Effects Of Explicit And Implicit Instruction In SLA

The objective of this study is to investigate, within the actual second language classroom, how and to what extent the effects conducted by the language learners at three different levels of proficiency acquire the two grammatical structures via the explicit instruction and implicit instruction. And intend to examine whether or not the effect remains in the long term, especially for these senior high school EFL (English as a Foreign Language) learners in China.The design itself is a factorial experimental study with three main factors: 1) teaching approach (explicit vs. implicit instruction); 2) English proficiency (high, mid and low), 3) task complexity (simple vs. complex).This long procedure consisted of three months owing to the two grammatical structures, i.e. the simple structure (subject-verb agreement) and complex structure (relative clause). The subjects were from three senior high schools of 236 students. These subjects received treatment from the 6th October, 2008 to the 25th December. The post-test was carried on the 26th, 29th, and 30th for the different English proficiency level subjects. In other words, the explicit and implicit classes of three English proficiency levels, both received the treatments over the six weeks from the same teacher, following the textbook syllabus, the explicit and implicit instructions employed on the subject-verb agreement. Hereafter the subjects learned the complex structure-relative clause- under the same condition, which was to exploit the explicit and implicit instructions. It also lasted six weeks. Further, in order to investigate the durability of the effect of explicit and implicit instructions, delayed-post-test was given at the 17th, March 2009.The subjects did not receive further instruction focused on the structures between the post-test and delayed-post-test, for the Spring Festival. Analysis included both statistic quantitative analysis and qualitative analysis.The results of the t-tests showed that first, there was no significant difference that was found between explicit and implicit group on the performance of the post test. Explicit approach was as effective as implicit one in English grammatical structures. Then, for the grammatical structures, the simple and complex structures, i.e. task complexity did not interact with teaching approach. No specific teaching approach advantage was found in teaching simple (subject-verb agreements) or complex (relative clause.) Significant proficiency-by-treatment (teaching approach) interaction was found. High-English proficiency learners significantly benefited more from explicit instruction than from implicit. Mid- or low- learners had equivalent performance for both teaching approaches; specific teaching approach advantage was, not found in either type of learners.The study concludes that the explicit and implicit instructions are both effective for students'grammar learning, also tests some of those theories in actual L2 classrooms of three senior high schools. And the research will focus on the acquisition of two different grammatical structures: simple grammatical structures, i.e. subject-verb agreement and complex grammatical structures, i.e. relative clause, by language learners at three different levels of proficiency, and will also address the durability problems with explicit and implicit instruction on learning varied grammatical structures by these senior high school learners in an EFL context.