The popularity of social networks and particularly of Facebook among university students implies a clear educational potential. In a preliminary study, it was found that most of the 1 st year students at the Department of Computer Science and Technology (University of Peloponnese) use Facebook daily and many hours per day. It was decided that Facebook would be used as a complementary teaching tool for the course of “Research Methodology in English”(1 st year course). In total, 66 students attended the classes, all between 18-19 years of age. The course instructor created a new profile on Facebook (not a specific group, but seen as a physical person) and asked students to send friendship requests. The vast majority of students included the instructor in their friends’ lists (55 friend requests). The students were also aware that this was a research process and their participation is valuable. From the first day of use, the students were given a usage diary and were asked to fill in at least 5 logs each, in which they should write down the date of use, the duration, the medium (PC, mobile phone, etc.), the purpose of visit, difficulties they faced, any other comments. The diaries were collected at the end of the term. In addition, students were asked to answer a small questionnaire at the beginning of the term, to identify their cognitive style, since one of the main research hypotheses was that social media might be more beneficial for certain cognitive styles, rather than others (ie extroverts vs. introverts).