I'm working on a research and I need references to studies, papers, web pages, etc., to know how a computer based system could in the future detect when a student is not understanding a topic of a lecture by detecting the emotions expressed in a student's face. So, imagine you are a Professor and you are explaining a new concept to the class. Maybe you see on your students' faces a confusion or surprise feeling that tells you they aren't understanding well the concept you are explaining. That's what I need, I need a source, reference to a paper or any oficial source of information to proof that what I'm saying aren't just word, but it is proven by researches. I want to prove that certain emotions can tell us the weaker knowledge points of students. All I've found is about how positive/negative emotions affect academic achievement, performance, etc., but I want to focus on the association of weak knowledge points with emotions, how we may know a student isn't understanding a topic by the emotion he is expressing.
Thank you so much and I hope I've explained myself.