This paper reports on a study examining the effects of visualizing online writing activities on student behaviors and learning outcomes. A design-based research approach was adopted to develop and integrate theory and practice in natural educational settings (Anderson & Shattuck, 2012). The study was conducted in an 18-week, semester-long undergraduate English for freshman engineering students course. The course was in a blended face-to-face/online format, using Moodle, and covering the four skills of listening, reading, speaking, and writing. A blog visualization tool, designed as a monitoring system visible to the instructor and all students, was implemented throughout the semester. Data from 28 students were analyzed, with the students' written consent. A mixed-method design was chosen for triangulation, using three data sources: pre-/post-course writing proficiency tests, an online post-course questionnaire, and online writings on Moodle. The research found that the self-regulatory mechanism supported a regular and high level of work performance of the entire class. The class average scores on writing tests showed gradual and steady progress. In addition, the phenomenon was observed in which students showed indecision about whether to work more or less relative to the performance of other students. Those students eventually deciding to work less showed certain regression in writing proficiency at the end, even if they started at a higher level than the class average. This situation, called the "to-do-or-not-to-do dilemma," is considered a potential negative effect of the monitoring system. A monitoring system for self and others can be a positive factor that improves the regular work performance of a learning community, leading to a higher outcome. However, the study suggests the need for appropriate counter-measures against possible demoralization in the individual and/ or the entire class. [For the complete volume, see ED574893.]