by Richard Oelmann.
I'm not sure about the practicalities of assigning individual activities to individual students, but if you don't want to or can't use groups, then would conditional activities be of any use to you?
Make the activity conditional on something like a single question quiz - the question is to enter an access key provided by the tutor when a student is ready to do an activity (or based on achievements in other aspects of the course already in place, depending on what is suitable for your structure)
We have used this idea in the past in a course which has students enrolling throughout the year, so it is not practical to have set dates on certain resources, or to administer the number of groups that would be needed.
Hope that helps