Why is it important to exceed the target or have a target which can be exceeded?
Clearly an A* cannot be exceeded! but as a top grade it is something to aim for and a good target for an able student.
The targets are usually based on something which is computer generated (based on SATs, MidYis tests..like IQ tests) but also teacher judgement. So, SATS and Mudyis might pedict that a student should be able to get a B. The teacher will use that as the starting point and decide if based on their knowledge of the child, that is about right. Rarely will teachers lower the target, but they may well raise it. So I have pupils who the computer tells me should get a B, but I know they can do better than that from the fact I have taught them for a couple of years....so I will make the target an A.
Targets should be aspirational but achievable. Those 2 words are very important. The is no point in having something which is impossible, but neither is it worth having something which is too easy either.....some schools call it a Challenge grade for this reason.
In some schools the pupil is involved in agreeing the target/challenge grade....so a discussion might be held as to whether they want to aim for a B or A.
Personally, I think that most students cannot answer this question early on, because they don't know what an A or B looks like or what will be involved. I think the teacher is in amu h better position to know what is possible and likely.
There is a balance to be had. On one hand, pupils should not be out under ridiculous pressure.....so it's important they know that the target IS achievable and not a pipe dream. At the same time, they need to be encouraged to be aspirational and not to settle for less than they could achieve.
It's worth mentioning that many A Level courses will require an A in that subject at GCSE in order to do it at A Level these days. GCSEs go on UCAS forms for Uni entry.....aiming for the the higher grade,will be beneficial in the long term. At the end of the day,they will get what they get, but aiming high is always good.