## Thursday, June 19, 2008

### Eleven Plus Conversations

One of the planks of selection and the Eleven Plus examination must be that there is a degree of correlation between the Eleven Plus and future academic success.

Correlation between two sets of marks is the extent to which they are similar – or the extent to which they agree. The precise extent of agreement is measured by means of a coefficient of correlation. A Coefficient of Correlation is shown in a range between -1 and +1. The extreme of +1 is perfect correlation while -1 is the opposite. If there is 0 correlation then there is a complete absence of either positive or negative correlation.

We could try to establish a degree of correlation between girls who pass the eleven plus and girls who take science at university. Are girls who pass the Eleven Plus more likely to go on to university to read science?

A different approach could try to establish the correlation between children who read widely and scores on verbal reasoning tests. Does lots of reading really have an impact on good scores in tests? We would need to investigate if good readers are able to cope with verbal reasoning papers.

To obtain a result of `0’ we would to investigate the correlation between two different events. We could look at height and the passing the Eleven Plus. We would need to hope that the height of a child is completely unrelated ability in competitive examinations. We would need to think that most children are fairly near to average in height. We would also need to think most children are fairly near to average in height. We can not predict that only tall children will pass the eleven plus.

Key playground conversations:

“I was looking into correlation last night. We think that there is a good chance of our child passing.”

“Look at those Year 5 children. They are so tall. I wonder how many will pass the Eleven Plus?”

“Every year our school gets 23 around out of 26 into grammar. My boy is in the top group. I think that it is likely that he will pass.”