Usage modes

Generally speaking there are two main forms of usage for a shared editor:

• Collaborative editing of a passage of text
• Annotation of a passage of text

In practice, when working in groups, we observe that shared editors also get used to a degree as additional communication channel, but this can largely be though of as annotation, even though these meta-annotations are not directly associated with existing text. Thus it is important for a shared editor to be able to easily support both these communication modes as transparently as possible.

If we satisfy the interactivity requirement above, it is vitally important, whether annotating or modifying text, that the person making a particular change is easily identifiable, even though several changes may be being made simultaneously.