If you would like to create a scored query that shows KB documents based on the Assignee, use the following WHERE CLAUSE:
ACTIVE_STATE=1 and ASSIGNEE_ID=U\'XXXX\'
For example:
ACTIVE_STATE=1 and ASSIGNEE_ID=U\'7D82EF5A1425A7428D77DBDCE75185B1\'
The result will show all KB documents assigned to that particular user and the status of each document