As in, how do the school ensure the pupils leave with the appropriate adult?
Is there an age when pupils are expected to be old enough and sensible enough to only leave when they see their adult and to return if they're mistaken?
Our school currently has the policy of Y1s spotting their adult through the window and going out to them, unfortunately this has resulted with some overenthusiastic/impatient Y1s running out when their adult has not been there to collect them.