In the past, written questionnaires were frequently applied to the evaluation of study and teaching at universities. Now, the Internet is becoming more and more important for conducting evaluation studies as well. One hope, which is connected with the usage of online surveys at universities, is that students will be more motivated to take part in an online survey than in a written one.The paper investigates if this expectation can be corroborated empirically. We are looking for explanations of response rates in students‘ online interviews and are trying to examine if online evaluation surveys can be a source of empirically confirmed conclusions. On the basis of three different surveys at the University of Bremen, it has been shown that the response rates in online surveys are higher than in written interviews and that the data quality is comparable. Therefore, evaluation surveys via the internet are quite an interesting alternative to written evaluations.