ASQ is a Web application for broadcasting and tracking interactive presentations, which can be used to support active learning pedagogies during lectures, labs and exercise sessions. Students connect their smartphones, tablets or laptops to receive the current slide as it is being explained by the teacher. Slides can include interactive teaching elements (usually questions of different forms). In contrast to other existing platforms, ASQ does not only collect, aggregate and visualize the answers in real-time, it also supports the data analytics in the classroom paradigm by providing the teacher with a real-time analysis of student behaviour during the entire session. One vital aspect of student behaviour is (in)attention and in this paper we discuss how we infer --- in real-time --- student attention based on log traces ASQ collects.