Here are some statements for discussion that may help us in determining our strategies and planning of work.  Please feel free to add your comments to each of the statements, or add statements yourself.

Gottfried

The development of a set of preference items for user interface adaptation should be based upon various use cases, including a range of user groups and a range of contexts of use.

The set and structure of preference items for user interface adaptation depends on the context of use (applications, platforms, assistive technologies).  There is no universal set of preference items that would suffice for all existing contexts of use.

The set of preference items for user interface adaptation will never be complete.  New applications, assistive technologies and user interaction techniques will eventually require an extension of any existing set of items.

A flat set of properties (key-value pairs) is most appropriate for practical reasons.

In general, the user properties stored in a user profile should be based on requirements rather than functional descriptions of the user.  However, functional descriptions may help to efficiently derive requirements-based properties for the initialization or fine-tuning of user profiles.