The main concept of Flipped Classroom (FC) is to invert, or flip, the content of teaching in terms of what is done during the homework phase, compared to the activity in the class with the teacher. Traditionally, the students at higher education attend a lecture, accompanied with tasks to solve at home or in a colloquium arranged by the University. The FC model will alter this completely, giving the students the opportunity to watch the lectures at home using pre-recorded videos. When attending class, instead of listening to a lecture, the students spend the time in a more dialogue-based problem-solving activity. To capture this complexity, the poster proposes a conceptualization of FC within the Activity Theory Framework.