Which type of assessment if most valuable to students.
Obviously the best assessment for students is "AS" because the ultimate realization of gaining knowledge is the learner himself. This, however, requires maturity and confident introspection which is not necessarily present in all.
The better assessment is "FOR" learning as it in ongoing process and not necessarily an endpoint but from a 3rd person point of view, the teacher.
A good assessment nowadays and certainly the most popular is the "OF" assessment, the summative tool. Comparing against a standard is a good excuse to quantify performance but consequently "limits" what one can or cannot do.
So traditionally, good is better than best?