I. Introduction
MASSIVE Open Online Courses (commonly known by the acronym MOOCs) are open courses designed to provide educational content to a large number of participants through an online platform, and with free access [1]. The term was coined in 2008, and has become more and more popular since 2012, creating a new paradigm in education. MOOCs originally appeared to enable learners all over the world to gain access to introductory courses from universities. However, currently there are MOOCs about many different thematic areas and levels, and as Christensen et al. [2] have shown, the target learners are not only undergraduate students anymore: Anyone with an interest can take one of these courses.