Figure 4 For example, Terry and Chris are members of the DL Group . As such they may add or modify annotations in the CSD set . But they can only view the annotations in the Demo set . In this section, we will give some examples of how annotations are used in the ComMentor prototype. For a more complete description, see the Technical Report .
Annotations are of different types.
All annotations contain information such as who authored them when, and which annotation set they belong to. Each of the annotation types defines a number of additional attributes. For example, a tour annotation would have in addition the location to which it points. The type also determines the default client behavior once an annotation is selected. Such images are active anchors in that users can click on them to view the comment.