Design characteristics of virtual learning environments: state of research

► VLE design characteristics described in previous studies are often, but not always derived from adequate theories. ► VLE design characteristics were universally applicable to VLE in general. ► VLE design characteristics were mostly evaluated in a single application domain. ► VLE design characteristics were of different granularity, and hence of different expressiveness and usability. ► VLE design characteristics were abundant, but of limited congruence, systematic, and completeness.