Past research has uncovered ways to improve communicative competence, including task-based learner-learner interaction (e.g., R. Ellis, 2003) and task planning (e.g., Mochizuki and Ortega, 2008). Teacher-guided planning particularly increases the benefits of learner-learner interaction (Foster and Skehan, 1999). One component of communicative competence--pragmatics--requires special attention as it may be one of the most difficult aspects of a second language (L2) (Blum-Kulka and Sheffer, 1993). Judd (1999) had proposed that guided/structured practice of pragmatics should take place before open-ended production. To investigate this claim, this classroom-based, semester-long quasi-experimental study examines whether planning via computer-delivered automatized structured tasks (CASTs) can help develop communicative competence, including pragmatics. The research questions are: (1) What is the effect of task planning (via CASTs, in pairs with classmates, or no planning) on pragmatic appropriateness and fluency, accuracy, and complexity of oral responses? (2) How does this effect transfer to new tasks? (3) What are learners' attitudes towards CASTs and pair-work activities? Three groups of ESL learners participated in the study. The structured task group (N=17) engaged in planning via CASTs. Learners in the "pair-work" group (N=16) planned the tasks via role-plays in dyads. The control group (N=17) did not engage in planning. The tasks were role-plays focusing on pragmatic appropriateness. The specific type of planning that learners engaged in was rehearsal. The immediate effect of rehearsal was measured via gains on rehearsed tasks, while the effect of rehearsal on language development in general was measured via gains on new tasks at the end of the study. The results of mixed-design ANOVAs indicate that all groups improved on both rehearsed and new tasks only in terms of vocabulary diversity. All groups also improved on pragmatics on new but not on rehearsed tasks. First, these findings suggest that when performing speech acts, learners focus on improving informational content rather than fluency, accuracy, and syntactic complexity of oral responses. Second, pragmatic development may not be apparent immediately. In this study, the experimental groups did not differ on gains for any of the measures. If there are differences between rehearsal via CASTs versus rehearsal via learner-learner dyads, the use of a more interactive computer program that allows for the provision of feedback after rehearsal might be necessary to uncover them. While the experimental groups had the same learning outcomes, their discourse patterns during task rehearsal differed. The results do not provide conclusive evidence that task rehearsal is beneficial because the control group did not differ from the experimental groups on gains. However, the relative shortness of pragmatic instruction, lack of immediate feedback, access to pragmatics in the second language environment, and low proficiency level of the learners may have lessened the effect of task rehearsal on pragmatic development. The questionnaire data indicate that while 57% of respondents enjoyed both CASTs and pair work, most students favored one type of activity or the other partly due to their personal preferences. The findings are discussed in terms of implications for using CASTs in face-to-face, hybrid, or online courses. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com/en-US/products/dissertations/individuals.shtml.]