  With the increase of distance learning, in general, and e-learning, in
particular, having a system capable of determining the engagement of students
is of primordial importance, and one of the biggest challenges, both for
teachers, researchers and policy makers. Here, we present a system to detect
the engagement level of the students. It uses only information provided by the
typical built-in web-camera present in a laptop computer, and was designed to
work in real time. We combine information about the movements of the eyes and
head, and facial emotions to produce a concentration index with three classes
of engagement: "very engaged", "nominally engaged" and "not engaged at all".
The system was tested in a typical e-learning scenario, and the results show
that it correctly identifies each period of time where students were "very
engaged", "nominally engaged" and "not engaged at all". Additionally, the
results also show that the students with best scores also have higher
concentration indexes.
