[AdvantageEnglish]

Evgenia - I know what you mean regarding labeling of students...

I've seen similar problems in schools back in Australia where a relief teacher or new teacher to the school receives a list of student's names and a brief description of each student's personality, behaviour and general ability.

eg. "Michael: Very naughty and rude, talks alot in class and doesn't listen."

The first time Michael whispers to his friend, the teacher yells at him because she 'knows' that Michael is a rude boy who needs more discipline.
When Rebecca whispers, she gets a different reaction from the teacher because she is described as a "well behaved girl".

The perception of students that a teacher brings to the class affects the way the teacher treats the student - whether the perception is behaviour based or abilities based, the principal is the same. Therefore, pehaps it is possible for a teacher who has strong pre-conceptions of a student's abilities to be 'blind' to the student's true ability if it exceeds the pre-conception.

I would hope that the teacher could take a proverbial step back and assess the student's abilities with unbiased eyes...