Thesis (M.Ed.)--Chulalongkorn University, 2010

The objectives of this study were to: (1) investigate the effects of team teaching of Thai and foreign teachers of English in task-based instruction on upper secondary school students’ English oral ability; and (2) explore students’ opinions about team teaching. The samples were 40 Mathayomsuksa 4 students who studied at Nawamintharachinuthit Horwang Nonthaburi School, Nonthaburi province. The experiment lasted for 12 weeks. The Wilcoxon signed-rank test was employed to investigate the differences between the pretest and posttest mean scores evaluated by two parallel sets of English oral test. Students’ opinions about team teaching were analyzed by arithmetic mean, frequency, and percentage. Content analysis was used to report on the results of open-ended responses and learner interviews. The findings of the study revealed that students’ posttest scores were higher than their pretest scores at a significant level (p≤ 0.05). Students reported that the team teaching of Thai and foreign teachers in task-based instruction was lively and enjoyable. Students’ involvement and teachers’ support were promoted. And the team teachers were perceived as equal.