By helping to be active during large scale lectures, students remember better what is presented, and can better connect new knowledge to entry knowledge. In large scale lectures with more than 150 students, it is nearly impossible to manage personal, face-to-face discussions and interaction. Based upon positive experiences with enabling interaction via mobile phones a new form of interaction was tried in a second year Bachelor's course (722 students). Students could send in open comments and questions via SMS, Twitter or via mobile Internet. The lecturer built in blocks of time to respond to these questions and comments. Unanswered but relevant questions are forwarded to the forum of the electronic learning environment (Blackboard), enablin...