The grammar and the lexicon are fundamental elements of any language. In the context of a second language (L2), mastery of grammar and lexicon are critical for the purpose of comprehensibility (e.g., Saito, Trofimovich, & Isaacs, 2015), yet they are highly complex systems and therefore typically present difficulty to L2 learners at all stages of proficiency. In communicative and content-based L2 classrooms, teachers can address this issue by providing learners with form-focused instruction and corrective feedback on grammatical structures and vocabulary during interactions that are otherwise primarily focused on meaning. In the context of peer interaction within communicative and content-based classrooms, however, learners typically focus almost exclusively on meaning and rarely shift their attention to linguistic forms (e.g., Adams, Nuevo, & Egi, 2011). Consequently, peer interaction is a useful pedagogical intervention for the purpose of fluency development, but not necessarily for the purpose of linguistic accuracy (Sato and Lyster, 2012).The goal of this dissertation is to explore the effectiveness of form-focused instruction and peer corrective feedback to improve linguistic accuracy and thereby maximize learning opportunities during peer interactions that focus primarily on meaning. The study used a mixed-methods design to collect both quantitative data that provided information on the effectiveness of the intervention and qualitative data to gain insights into learners beliefs about the intervention. Two experiments were conducted: The first one was designed to promote the acquisition of grammatical structures and the second to promote the acquisition of vocabulary.In experiment 1, 87 third-semester learners of German were assigned to a PI group (peer interaction only), PI FFI group (peer interaction and form-focused instruction), or PI FFI CF group (peer interaction, form-focused instruction, and peer corrective feedback). During an instructional treatment over three consecutive class periods, participants in all three groups engaged in the same peer interaction activities that revolved around the city of Munich. However, only the PI FFI group and the PI FFI CF group received form-focused instruction on the grammatical target structure, the German present perfect tense, which includes auxiliary verb selection and past participle formation. Critically, only the PI FFI CF group was trained to provide corrective feedback to peers. A pretest and two posttests measured the effectiveness of the intervention, all of which included an oral production task and an error correction task. Results showed that the PI FFI group outperformed the PI group on all of the four auxiliary measures, but on none of the four past participle measures, whereas the PI FFI CF group outperformed the PI group on all auxiliary measures and two past participle measures. The PI FFI CF group outperformed the PI FFI group on one past participle measure, but on none of the auxiliary measures.In experiment 2, 77 third-semester learners of German were assigned to one of the same three groups as in experiment 1 and engaged in peer interaction activities that revolved around the discussion of the movie Almanya Welcome to Germany during an instructional treatment over four consecutive class periods. Only the PI FFI group and the PI FFI CF group received form-focused instruction on vocabulary relevant to the movie, which were 25 German nouns along with their gender and plural forms, and only the PI FFI CF group received training on how to correct peers vocabulary mistakes. Results from a pretest and two posttests showed that both the PI FFI and the PI FFI CF group outperformed the PI group on seven of eight measures assessing productive and receptive vocabulary knowledge, as well as knowledge of grammatical gender and plural forms. The PI FFI CF group outperformed the PI FFI group on three of four measures of productive and receptive vocabulary, but on none of the four measures of grammatical gender and plural forms.Overall, the findings of the two experiments suggest that peer interaction was most effective when combined with form-focused instruction, and even more effective when peer feedback training was also provided to learners, suggesting that peer corrective feedback is a useful pedagogical intervention in foreign language classrooms. These findings are complemented by qualitative data from semi-structured interviews, that showed learners held positive beliefs about peer interaction and peer corrective feedback, regardless of the treatment group they had been assigned to, although learners from the PI and the PI FFI group were more likely to withhold peer corrections due to social considerations. Qualitative data further showed that the noticing of mistakes, as well as peer corrective feedback, was most likely to occur in the PI FFI CF group. These findings are discussed within the context of the interaction approach (Long, 1983a, 1996; Gass & Mackey, 2015) and the noticing hypothesis (Schmidt, 1990, 2001). Pedagogical implications for foreign language learning in classroom environments are also discussed.
The grammar and the lexicon are fundamental elements of any language.
