There are a variety of tools you could use for this.
A feedback activity
Choice - although you may need a whole series of them, but may be good if you want to give a range of options - My understanding of XYZ is [great] [good] [ok] [needs developing] [Help!]
Checklist
or simply add a collection of statements as separate labels, and turn on activity completion tracking for them and allow the students to tick them when completed (when they think they have achieved them)
I've seen the first two used, but have used the second two myself - more frequently the labels with completion tracking as its so easy to set up and monitor (and one of teh sites i was doing it on didn't have the checklist plugin installed )
Richard