Class average - what would be considered a bad result?

[Anothermum2467]

Just wondering what is considered a bad/low score when you are given a class average? For example top set average class result in English is 84%, obviously anything above is good but what would be considered a low result, anything bellow class average?

Our school tells the kids the highest mark. Average is meaningless without context. You don't know if 5 people got 90+, 5 people got >20 and everyone in between or everyone scores between 74 and 94.

Kids won't switch sets based on one exam ime. My dd was in set 2 maths and wasn't moved up to set 1 until she was consistently outperforming most of set 1 (of 8) The top of set 2 and bottom of set are usually similar in ability.