The purpose of this paper is to compare those undergraduate university students who succeeded in improving their scores of TOEIC (Test of English for International Communication) through an English e-learning program and those who did not to explore the relationship between their TOEIC test score gains and their task completion rate and time on task. It was confirmed again that successful learners' average task completion rate was significantly higher than that of unsuccessful learners and their time on task was longer than that of unsuccessful ones. It was also found that the unsuccessful learners' likelihood of improper study was higher than that of successful learners.