Sketch: Changing and deleting is done in item-level views. The scenarios here should go over all of the details for each of the four types of scheduled items. The important issues include the following:

1. For meetings, when a group leader changes or deletes a meeting, all attendees must be notified.

2. For tasks, the completion status can be changed.

3. For recurring items, the user should have the option to change or delete a single occurrence, all occurrences, or all future occurrences.