The purpose of this action research study is to challenge accepted practice in ESL writing with the implementation of an experimental syllabus informed by a sociocultural approach, specifically Vygotsky's (1987) assertion of the key role that awareness and control of theoretical concepts plays in cognitive development. Following Gal'perin and Davydov, the classroom approach implemented here is essentially concerned with L2 development as the internalization, appropriation and control of conceptual meaning in the context of the goal-oriented activities of teaching and learning. This research and pedagogy calls attention to the importance of the quality and sequence of instruction, in which full and explicit attention is given to an abstract conceptual framework before learners proceed to explore concrete instantiations of the abstract concepts in question.Halliday's (1978) social semiotic understanding of language, text and context was the central concept presented to a mixed ESL and native-speaking composition class, and various activities and exercises were designed in keeping with the principles guiding this 16-week research project. Learners made use of didactic models and verbalization activities, including extensive collaborative writing, as they worked with the concepts and explored the ways in which the target academic discourse reflects Halliday's theory of language in use. These concepts were then applied in the writing of research, re-writing for a new audience, and reflection papers. Writing development was tracked using T-Unit analysis, lexical density measures, rhetorical move analysis and the ratings from three expert raters, who graded the resulting papers for language use, analysis and organization. In analysis, this proficiency development is related to evidence of re-mediated thought as the students collaborate to complete the assigned writing tasks.The findings of three case studies provide general support for the implementation of concept-based instruction and a theoretical and explicit attention to requisite aspects of the target discourse in ESL writing pedagogy. There is clear evidence that the concept-based approach fosters awareness and control over relevant features of the target language necessary for successful participation in academic discourse communities.

This thesis aims to bring together the area of pragmatics in second language learning (SLL), and dynamic assessment (DA), and in doing so offer an alternative way of both assessing pragmatics and providing its instruction. DA aims to provide a detailed analysis of not only a learner’s current stage of development, but also their still developing abilities. Unifying instruction and assessment, the learner and a mediator co-construct a task, with the mediator providing assistance when necessary. By examining both the types of mediation practices and their frequency, insights can be gained as to the learner’s still maturing abilities, and future potential. DA also aims to uncover sources of learner difficulty, offering a diagnostic function as part of assessment. Drawing on conversation analysis research, the work of Gal’Perin and DA methodology, this study carried out a DA of the speech act of requesting in spoken interaction, assessing the effectiveness with which the DA promoted development in the learners. Further, the ability of the DA to uncover specific locations of learner difficulty was examined, as well as the ways in which the interlocutors successfully negotiated the opening and closing of mediation sequences. Six Japanese EFL learners in a university context co-constructed a number of role-play type language tasks with the researcher. In the first stage of the study, the researcher did not offer support to the learners, while in the following stage, mediation was provided when appropriate. The findings were used to inform the enrichment programme (EP) portion of the study, in which the learners met with the researcher for a period of four weeks, receiving tutoring. This was followed by further non-dynamic and dynamic assessments, to allow analysis of learner development. The study’s findings indicate that DA methodology, when applied to the speech act of requesting, can be an effective way to both promote learner development and assess learners’ abilities. Compared with the pre-EP assessments, participants produced more complex interactions that frequently showed evidence of taking the social context of the role-plays into account, as well as assuming greater responsibility for successfully completing the tasks. Participants were also more frequently able to verbally explain their language choices with reference to the target concepts of the assessments and EP. Further, overall, the opening and closing of mediation sequences were accomplished with more implicit negotiation practices, indicating increased interactive competence. The DA was also successful in locating specific locations of learner difficulty.