This action research was undertaken at a university language center in Ambato, Ecuador, as a result of concerns over the high level of teacher dependence among learners of English as a Second Language (EFL). The project aimed at assessing the development of autonomous learning behavior and the motivational impact of student collaboration on encouraging a change in student behavior toward autonomy. The participating students were 154 EFL students of lower advanced levels who engaged in a 5-week intervention addressed at encouraging autonomous listening comprehension practice through videos. Participants used the Moodle® platform to share videos with peers of the same level, who were also able to post comments on the content of the videos. Quantitative and qualitative parameters were used to assess the achievement of two objectives: the extent of the development of autonomous behavior; and the extent of the motivational impact of student collaboration on encouraging autonomous behavior. Analysis of participation showed development of student autonomy when measured against three of the four parameters used. Analysis of feedback showed the platform-based collaborative learning strategy had a significant impact on student motivation and engagement during the intervention. Feedback included the recommendation to extend and improve the intervention, while complementing it with a medium to allow greater interaction in real time.