11 Plus Standardised Scores Explained

Many parents struggle to understand how the 11 Plus exam standardised scores are calculated. As tutors, we have to explain to parents every year, how the 11 plus exam scores are calculated because usually, scores from schools are given as a percentage or simply a basic x/a number.

Below is a summary of what a standardised score is and the reasons behind using this method for calculating the 11 plus exam scores.

So, what is a standardised score?

A standardised score is a number that is calculated using a standard deviation formula. It takes into account where that score sits in a cohort and is a statistical way of ironing out some variances to give a like for like comparison.

A standardised score takes scores that have differing numbers of questions and papers and gives a mean score out of 100 (though in the 11 plus the mean can be higher!). These scores are then organised into a lookup table based on the child’s ages (in years and months) and the mean score.

Each examining organisation will have a lookup table they will use to calculate the age-standardised score depending on the number of applicants, average student scores in each test.

For example, if one child gets a raw score of 125 on one test and a raw score of 30 on another test, how can that be compared to another child who gets 98 in one test and 113 in the second test but is also 3 months younger.

To make sense of these scores in relation to other children’s marks, we need to work out what these scores are in relation to the overall mean scores of the cohort. But this still does not give us a full picture because each test is different.

So, let us say that a child’s score is 10 points above the mean in one and 3 points above the mean in the other. These deviations make it difficult to calculate exactly how well or badly the child did in the papers compared to every other child. Hence the need for standard deviation.

Standard deviation will work out how many points the overall score of any child is from the cohort average. By removing variable elements of each test score (child’s age, ability and level of difficulty of the paper).

So, for example, if the child needed to attain a standardised score of 132, a child who is exactly 10 years old will need to attain a raw score of 67 out of 80, whereas a child who is 10 ½ years old will need to attain a score of 78 out of 80

From the standardisation process, the 11 plus scores will emerge. The lowest score is usually around 70 and the highest score will usually be around 140. Achieving 140 will mean your child is in the top 1% of all those who took the test. Exceptionally high scores (above 140 or 141) are often not recorded as the variances will be minimal. This, however, is not true of all boroughs as we have had children achieving perfect scores and the scores are shown as higher than 141.

How are the places allocated?

In many boroughs, places are allocated in descending order by score and there is no cut-off point. Simply, the borough will work top-down approach where they will take the top x number based on the number of seats available.

The standardised scores are based on a bell curve:

For further information about past “minimum standardised scores” (i.e. pass marks or qualifying marks) required for entry to schools in your area click here.

How can I work out my child’s standardised score for practice papers?

We have created a chart for age-standardised scores to help you work out roughly what score your child is achieving.