 At the Faculty of Psychology of the University of Vienna, Twitter was used for formative course evaluation.Summative student evaluations of teaching (SETs) have been widely criticized, especially by teachers, for not being accurate measures of teaching effectiveness.Surveys have shown that a majority of teachers believe that a teacher's raising the level of standards and/or content would result in worse SETs for the teacher, and that students in filling out SETs are biased in favor of certain teachers' personalities, looks, disabilities, gender and ethnicity.