training - layer 2
why pre assess?
The sooner the teacher pre assesses ahead of teaching the more accurate 
...
... and the more useful the data is.
How to create a pre assess assignment
The two example mp4s (in the link above) are examples of creating pre assess assignments, following a pre-assess plan which marries with a scheme of learning.
Follow your scheme of learning to know when to create a pre assess assignment.
Follow you pre-assess plan to know what to pre assess.
How to assess a pre assess assignment
The mp4 in the link above shows how to do this.