This paper discusses the concept of diversity of course components in the context of an online staff development course at the United Kingdom Open University. In addition to FirstClass computer conferencing and Web content, RealAudio was used in both synchronous and asynchronous modes. The purpose of its use was to add diversity and focus, which would maintain active participation until the end of the course. Following a description of the aim and components of the course, this paper presents an evaluation of its effectiveness and draws conclusions about an appropriate level of media diversity. Two figures present a snapshot of one of the audio annotations of the course materials and the opening screen of the FirstClass course area. (AEF)