Every now and then the minds of some parents must wander in the direction of: “How well is my child doing towards the Eleven Plus?” Suppose your child is at a mixed school where there are two Year 5 classes. You could obtain some data from the scores of all the children in the year group.
In one scenario the school could usually help around 27 children to pass the eleven plus in any given year. A different school could reflect on why only three or four children out of the year group pass.
You could obtain a lot of data from looking at the scores from the children’s results. It would be considerably less easy to try to work who is going to pass by trying to predict pass scores. It may even be easier to try to work out whether more boys than girls will pass. In this exercise there are thirty boys and 20 girls.
The chances of more boys than girls pass is random.
The chance of more boys than girls passing is not random.
Decisions on whether more boys than girls are likely to pass can only be made if it is accepted that some ten year old girls are more likely to pass than some boys. If this hypothesis is also rejected then it becomes even more difficult to predict which boys and which girls will pass.