Roles can be assigned to occurrences of variables in programs according to a small number of stereotypical patterns of use. Studies on explicitly teaching roles to novices learning programming have shown that roles are an excellent pedagogical tool for clarifying the structure and meaning of programs and that their use improves students' programming skills. This paper describes how roles can be applied in various programming paradigms and presents the results of three studies designed to test the understandability and acceptability of the role concept and of the individual roles in procedural, object-oriented, and functional programming. Based on the results, two new roles and small modifications to the definitions of the original roles are suggested. (Contains 6 tables and 3 figures.)