Microblogging tools such as Twitter have been frequently adopted in educational settings to facilitate learning in recent years. Although the original purpose of microblogging tools is to connect with others in a wide network and instantly share what is happening to them with the rest of the world, educators have vigorously attempted to repurpose the utilization of the tool and integrate it into various educational settings to promote student learning. The purpose of this study is to examine student learning experience under a set of structured microblogging-based activities and to identify the affordances and constraints of the technology. Students participated in the structured microblogging-supported collaborative and reflective activities during the class and reported their learning experience afterward. The analysis of in-class discussion transcripts, microblogging posts, pre- and post-survey results, and the after-class blog posts suggested that the structure provided by the instructor in these microblogging activities, allowed students to focus on the learning content and participate in an effective manner. The students' in-class participation and engagement were elevated by the microblogging-based activities, and they had an increased positive attitude towards the educational use of microblogging after the class activities. This research suggests that providing structure to microblogging activities is critical to maximize the affordances and minimize the constraints of microblogging tools in a classroom setting. Specific structuring strategies employed in this study, such as presetting a code of conduct for tweeting, providing scaffolding to each tweeting activity, and setting a limited time frame, are worth considering for a successful microblogging application. (Contains 1 figure and 2 tables.)