Understanding Standardised Scores

Standardised scores - what do they mean?

Standardised scores are a valuable measure of performance. Instead of reporting a percentage score or a fixed number of points, standardised scores compare performance against other test takers and can rate it against a defined group - such as other students of the same age, or year group, or those following a similar learning pathway (e.g. medical students for example). The most common standardised tests compare candidates against a national standard and are usually based on the candidates’ age - these create Age-Standardised Scores (SAS) - that can, when used correctly in the context of a specific learning environment, provide valuable insight into a student’s learning trajectory and that of the group as a whole. This kind of measure describes performance as how close a candidate is to the average. This is usually illustrated using a bell curve to show where candidates fall in comparison to a defined ‘normal range’ usually defined as one standard deviation either side of the average score.


The area under the curve reflects the proportion of candidates performing at that level, so the vast majority of candidates fall between one standard deviation of the average. Outliers who score above or below one standard deviation might be considered statistically stronger or weaker (respectively) to their peers according to this methodology.


What is a good score?

A “good” score varies depending on the kind of school or long term outcomes you might be aiming for, and how many places are available. There is not a pass or fail score on standardised tests, as candidates are being compared against others of the same age. An average score is 100, and two thirds of candidates will fall between 90 and 110 on our test. However, the average score for students applying to certain selective schools might be as high as 114, however these types of schools are few and far between - many great schools simply expect applicants to be average (95 - 105) or high average (105 - 115). Also, it is important to note that standardised tests always come with a margin of error of +/- 3 or 4 points so focus less on a specific figure, and more on what the overall profile is telling you.


Can I just learn the material on the test?

In short, no. Our tests, and others like it, contain 1000s of questions and there is little benefit in trying to learn the answers (see our explainer on Adaptive Tests). These tests are measures of skills not knowledge, so spending time trying to strengthen maths or literacy skills will help students perform better in these tests. Generally, skill development takes time and short term tutoring or cramming has little effect on these sort of assessments. However, dedicated practise - with a skilled tutor and quality sample material can make a positive difference. We can direct you to good support organisations if you need help in this area.


And remember, the academic score is just one aspect of your application to a future school; there are interviews and the application form to get right too. This is where an expert can help you navigate the different processes and put your best profile forward.