Sdr, Mark Handley’s session directory tool, has in the last year undergone some changes beyond those that Mark Handley himself has instigated. During a student project which involved a language based approach to conceptual design, a new design model for sdr was found, and the words used in sdr’s interface were changed to reflect sdfg sdthe new design model.

Redesigning the user interface of sdr involved three stages:

1. Identifying a suitable basis for a design model;
2. Applying the design model to sdr;
3. Communicating the design model through the user interface.

Identifying a Design Model

To find a suitable metaphor to use as a design model, existing users of sdr at University College London were interviewed, and questionnaires were sent out to existing users at other sites in the UK and Europe. The aim was to establish

• which tasks existing users apply sdr to
• which existing functions were most frequently used
• which existing functions users felt were most useful

The responses showed that the most common use of sdr was to see what multimedia events are taking place on the Internet. 11 out of the 16 users who answered the questionnaire use sdr to see what sessions are on more than 3 times a week. 7 users join a session from sdr more than 3 times a week, and only 3 users set up sessions more than 3 times a week.

Existing users were also asked how they would explain sdr to a user who was new to Internet conferencing and sdr. Two metaphors emerged from the explanations:

• "Radio Times", a weekly TV listings guide, and
• "Yellow Pages", a telephone directory for businesses.

Both metaphors were compared to sdr and it was decided that the "Radio Times" covered most of its core functionality. The broadcasting domain of the "Radio Times" - selecting or locating TV or radio programmes, and maybe recording them - is more closely related than the telephony domain; for instance, sdr has a strong notion of time built into it which is not covered in the Yellow Pages metaphor. Since the task most existing users apply sdr to, is seeing what sessions take place and when they take place, this is a key element that the model needs to cover.

In order to reflect the fact that the "Radio Times" is a paper based medium, and sdr is electronics, a so far non-existing electronic "Radio Times" was chosen as design model for sdr.

Applying the Design Model and Communicating the it Through the User Interface.

As mentioned above, the approach to conceptual design in this project was language based. Labels and terms which appear in the user interface were believed to be an important vehicle for communicating the design model through the user interface and supporting the construction of a user’s model. It was therefore important to establish the terms the "Radio Times" metaphor would evoke in potential new users of sdr. Does a TV programme have a name or a title? What is the bit underneath the name called - summary, review, description? General broadcasting terminology was also considered in an attempt to make the entire user interface linguistically consistent with the metaphor. Another issue was how to deal with the fact that the design model is an "Electronic Radio Times". To find answers to these questions, 14 potential users were interviewed, recruited from UCL staff and students, and employees of a major UK bank, representing a diversity of people as prospective sdr users would be, and none of them with previous multicast conferencing experience.

From the interviews we identified the words and terms in which users described the "Radio Times". The words and terms identified from the interviews were then used in sdr’s interface to reflect the design model. Sdr’s online help system was also rewritten to reflect the new design model.

A description of the evaluation of the new interface can be found in chapter 4.