Comparing apples and oranges: percentage scores and standardised scores in Bexley, Bromley and Kent.

Understandably, parents want to know whether the percentage scores their child's receives in ten-minute test books and assessment papers is "good enough" for the Bexley/Bromley/Kent tests. Specifically, a magic percentage is sought, a more-or-less definite threshold at which we know we are in or out: "On average my child scores 65%, would this be enough to pass...?" When my daughter came from her dance class with her certificate, she said, "I don't think anyone received a distinction this year."

I said, "That's good. That means there is an absolute standard in the dance school. If everyone's good enough to get a distinction, everyone will get one. If no one's good enough, no one will." So, with 10-minute tests and with my daughter's dance school grades, we are dealing with absolute values. But with the 11+ exams of Bexley, Bromley and Kent we are dealing with relative values. And comparing absolute values to relative values is like comparing apples to oranges; we are talking about two different things. My response to a parent who asks, "Which percentage score is good enough to pass?" I may say "75%" or "as close to 100% as possible", because I don't want to sound evasive, and the alternative, more accurate, response - the response I give here - is difficult to make in a succinct way: When your child completes a test at home, they get a score (e.g., 10/12), which a parent will probably convert to a percentage score. Whether we're speaking of 10/12 or 83.3% is irrelevant: what is relevant is this is an absolute score; this is your child's score compared to nothing and no-one (except his or her own previous performances). When your child completes the Bexley or Bromley or Kent exams, they will receive a standardised score: this is a relative score. The absolute score that your child scored in the test is unknown to you and is irrelevant. What matters is how your child scores relative to other children in his/her exam cohort. Let's just, for argument's sake, say that you did know that you're child scored 80% in an exam. If this exam were easy - as some years it might be - and the majority of the cohort scored higher than 90%, your child might not achieve selective status. This is an extreme example, theoretically possible but not likely in reality, but it should illustrate the point. Conversely, your child might score relatively poorly but if the majority of cohort score even worse, then your child may still achieve selective status. This is why the result you will receive on exam day will represent how your child has done relative to other children, rather than how he/she had done on his own terms. This is called a standardised score. Some exams receive a further standardisation - called age standardisation - which is a formulaic way of resolving the problem of the gulf in development between a child born, let's say, in September and one born the following July. This adds a further dose of relativity to your child's score: your child's absolute score might be the same as another child's, but if your child is born early in the year and the other child late in the year, the other child will score more highly. I say all this so that parents are aware that there is no magic score that you can consistently achieve in your CGP/Bond tests (or whatever) from which to derive a guarantee of success because your assessment papers that your child completes at home are apples and the 11+ exams (at least the ones we are concerned with) are oranges.