What are standardised scores?
Most of us understand scoring systems like those used in our
schools, ‘7 out of 10’ or a percentage score say 70%. Such scores, known as raw
scores, are easily understandable and useful in indicating ‘how many you got
right’. However, these scores are less useful in enabling teachers to compare
pupils’ performance meaningfully between one test and another, and to monitor
progress over a period of time. This is because raw scores do not account for
factors such as
- varying difficultly of a test from year to year.
- Varying aptitude and number of students giving the test
These factors would end up making the average scores (and
hence selection scores) subject to large variations year on year. Further
section wise variation in number of questions means a simple a one to one
comparison of the raw scores would give certain sections more weight-age.
To overcome these challenges, standardised scores are used
instead of raw scores as they help balance the overall performance of children
from one year to the next as well as importance of various sections within the
The process of standard score calculation is relatively
complex, in this article we will try and discuss the basics for interested
parents/students but remember you don’t have to dwell on the detailed mechanics
– it all comes down to attempting questions in a considered, accurate manner
and keeping pace with the speed of the test.
What is age-standardised score?
The standardised scores achieved by each student (as described
above and explained later on in this article) are age-standardised. This
basically means that the scores are modified slightly to give a small
additional score to children who are younger within the year group.
Such adjustments are used because in extreme circumstances
there can be up to a year of difference between the ages of the children taking
the test and older children naturally:
- Can concentrate harder and longer
- Have a wider vocabulary than younger class-mates
- Display greater comprehension ability
- Are able to work quicker and with greater accuracy
- Deal better with exam stress
Although this may be concerning for some parents and
children (and equally euphoric for others), it is worth remembering that the
factor is very small and the most important parameter remains test performance
On our website we do not collect the ages for children and
hence do not use age-standardisation in our score analysis.
What score is required to qualify the 11 plus?
Each county can have a varying criterion, below is the
specific one used by Buckinghamshire county council but the basics remain
similar and we daresay the system can help parents/students from other areas as
well as its primary a bench-marking tool – it’s getting a good score that
In Buckinghamshire, by achieving a STTS (standardised
Secondary Transfer Test Score) of 121 or a child is considered suitable for any
grammar school within Buckinghamshire, subject to catchment area and other
admission policies. This score cut-off of 121 can remain constant from year to
The average score is 100 and on average 33% of children are
expected to get an STTS of 121 or more. The score range can be between 60 on
the lower side and the highest score 140 or 141.
How should I evaluate my score?
If you have taken one of our ’Online Mock Exams’, you would
have received a score analysis report with a ‘Projected Test Score’. If your
projected score is:
A) Projected Test Score of 125 or more:
The score of 121 or over indicates a pass in the Mock Exam,
congratulations for achieving that comfortably! It is important to continue
with regular practice but avoid getting ‘Exam fatigue’ which can set in if you
overdo it. We recommend diversifying your reading habits which will not only
help you do even better at verbal section but also develop your language skills
B) Projected Test Score between 115 and 125:
Even if this is on the borderline of a pass (over or under
the line, ever so slightly), it’s worth remembering that this is a great score!
With the average score being 100, you have performed much better than your
peers. With regular practice and regular habit of learning from each question
that you got wrong, you can easily push your score over the line in the final
exam. So well done and keep up the good work.
C) Projected Test Score between 90 and 115:
If you are in year 5 and looking to give the test this year
in September, there is a currently a gap between achievement and needed score.
We recommend a thorough revision of fundamentals and regular exam practice.
Pass is achievable through dedication and honest work – think how proud you
will be when you clear the exam!
D) Projected Test Score less than 90:
If you are in year 5 and looking to give the test this year
in September, there is a need to do a lot of fundamental revision, practice and
exam prep. A lot of the content stems from the basics you have been learning as
part of your school curriculum, so you can definitely improve your score by
leaps and bounds.
It is worth remembering that sometimes you can just have a
bad exam day or the exam pattern may be relatively new to you. Focus on
improving the score rather that dwelling on a low score.
Watch a motivational movie (we recommend ‘Rocky’ series) and
let’s get to work!
Whatever your child’s score, in case you need support with:
- Good reading suggestions
- ‘Brain workout’ ideas
- Additional practice questions
- Fundamentals revision
- Mock Exam analysis
- Motivation session for the exam
Please feel free to ask for support on our Facebook support
group (link below) and we will do our best to advise.
How scores are calculated?
To understand how the process of score standardisation
actually happens, one need to understand the basics of distribution, normal
distribution and basics of transformation of any distribution into normal.
Step 1: Standardised Scores
The test results are broken down into three elements
(Verbal, Maths and Non-Verbal) and the raw scores from each element are
separately standardised using the formula:
S = n (x - y)/ SD + 100
In this process essentially, we are transforming the
distribution of actual results (which has a mean of y and standard deviation of
SD) to a distribution with mean 100 and a standard deviation of n.
x is the achieved raw score
y is the mean score of all students who have taken the test
SD is the standard deviation of the sample
Step 2: Weighted Standardised Scores
The three Standardised Scores elements (Verbal, Maths and
Non-Verbal) calculated above are individually weighted as follows:
The weighted Verbal score is 50% of Verbal Standardised
The weighted Maths score is 25% of Maths Standardised Score
The weighted Non-Verbal score is 25% of Non-Verbal
Step 3: standardised Secondary Transfer Test Score (STTS)
The three weighted scores are added to give the standardised
Secondary Transfer Test Score (STTS), the score is always rounded down to a
Please Note: The Projected Test Score is based on your
performance in the stated test and is a projection based on sample and actual
test data from other students on our platform. The projection is meant to be
used solely for the purpose of setting performance benchmarks on our website
and in no way attempts to predict the performance in the actual exam. We have
compiled this information to the best of our knowledge but cannot give any
warranty to its accuracy, not do we claim to be partners with the concerned
councils to disseminate this information. Individual councils have varying
admission criteria and we encourage all parents to see the applicable council
website for more information on the local admission process.