Score vs percentage

[Skylark]

Hello,

I understand that the cut off for King Edward Camphill for girls was 235 last year. Does anyone understand, how much is this in "percentage"? How much is it out of?

Many thanks in advance.
--NK

Wouldn't it be brilliant if results were out instantly. Sorry I can't be of much help with your question. I am sure ones the results are out- we can then plan on the next step. Until then we are in limbo.

Gosh yes... that would be brilliant. Once the results are out, you will have a clearer idea as how to fill the CAF form out.

From what I recall when my oldest DS took the exams (8 years ago) we were unaware of their results and just put the school we wanted and hoped for the best.
At least now we have an indication as to whether they will realistically get a place.

That sounds terrible, fill the form in before knowing the results

Must of been more of an anxious wait, glad that is not the case anymore.

[MSD]

That is such a useful link Candel. I had ones seen it and couldn't find it again. This forum is full of insightful information. It would very good, if each post had a 'like' button next to a post and you could find it again.

Good to see the post we started a while back with the primary purpose of helping potential 11+ parents with SD vs RAW SCORE jargon is being used

[MSD]

Hello,

I understand that the cut off for King Edward Camphill for girls was 235 last year. Does anyone understand, how much is this in "percentage"? How much is it out of?

Many thanks in advance.
--NK

As other posters have pointed out, it would be difficult to work out the actual percentage. However, there is a formula I have somewhere, which will approximately tell us the number of candidates scoring above that SD if we knew the total cohort size sitting the test. I will try to dig that out for you.

You can possibly get some idea on the percentages if we look at some of the old stats we received from Birmingham consortium for 2015 results, quoting Data Protection Act

To achieve an average SD score of 200, below were the raw marks and percentages required


Verbal Reasoning: 53.82/110 (48.92%)

Non Verbal: 29.43/53 (55.5%)

Numerical Reasoning (Maths): 22.22/44 (50.5%)

To achieve an SD score of 221, below were the raw marks and percentages required (October birth)


VR: 15/28, 16/25, 21/25, 13/18 and 11/14
NVR: 11/21 and 23/32
Maths: 14/20 and 13/24

So 69% in VR for a score of 115 and 63% in NVR/maths for a score of 106.

To achieve an SD score of 258, below were the raw marks and percentages required (Early September birth)


VR: 21/28, 20/25, 24/25, 16/18 and 14/14
NVR: 18/21 and 30/32
Maths: 20/20 and 23/24

English SD - 130
Maths/NVR SD - 128

Total SD - 258

So, 86.36% in VR and 93.8% in NVR/Maths

5574 total candidates registered to take test in 2015

Hope this helps!

[MSD]

I understand that the cut off for King Edward Camphill for girls was 235 last year. Does anyone understand, how much is this in "percentage"? How much is it out of?

Here's is the formula Kumar..

S = 15(b — a)/sd + 100

where S is the pupil’s standardised score, b is the pupil’s raw score, a is the average raw score of all the pupils, and sd is the standard deviation of the raw scores - CEM I believe have used 12.5 as the deviation, but obviously this can vary but only marginally.

The above formula is really based on you knowing the average raw score achieved by all cohort sitting the test. But, in your instance, let's use 2015's average raw score and try working it out.

VR Section

Assume child achieving 65% actual raw in VR and 48.92% being cohort average

S = 15(65 - 48.92)/12.5 + 100 = 119.29

Maths/NVR Section

Assume child achieving 66% actual raw in Maths/NVER and 53% being cohort average

S = 15(66 - 53)/12.5 + 100 = 115.6

That gives us a total of 234.89 SD, which is pretty close to the score you were looking for. So to achieve SD of 235 you would approximately need 65% raw in VR and 66% raw in Maths/NVR based on the above inputs.

PS - This is a rough guide and year on year cohort averages could be different, but I would assume not by much. And you have to also factor in the age standardisation.

[Candel]

Thanks MSD. I've found many of your posts, and those of your contemporaries, very helpful!

[MSD]

Thank you Candel!

[kumarkj]

Thank you MSD. It was really helpful as it gave me a very good view of the calculation and perhaps expected score.

[MSD]

Thank you MSD. It was really helpful as it gave me a very good view of the calculation and perhaps expected score.

I am glad you found it helpful. In my previous post I mentioned that you can approximately work out the actual percentile of the candidate from his SD and essentially the rank order, if you knew the total cohort size.

Let's take an example of the below real score we received in 2015 from one of the parents for Child A(Early September birth) and try to find approximate percentile and rank order.

VR: 21/28, 20/25, 24/25, 16/18 and 14/14
NVR: 18/21 and 30/32
Maths: 20/20 and 23/24

So, 86.36% in VR and 93.8% in NVR/Maths

VR SD - 130
Numeric/NVR SD - 128

Total SD - 258

5574 total candidates registered to take test in 2015

Here's the Z-number score formula:

z = (x – μ) / σ

where

x - SD score
μ - Mean SD score (For Birmigham it is 100)
σ - Standard deviation (Let's use 15 in this case but could slightly vary)

We need to now find the Z-number first for SD in each section. Let's start with VR

Verbal Reasoning Z-number

Z = (130-100)/15 = 2

A Z of 2 gives us 0.9772, which equates to approximately 2.28% scoring higher for that subject area. Approximate Rank Order out of 5574 - 127

(Try this http://www.doe.virginia.gov/testing/sol ... _a2-11.pdf" onclick="window.open(this.href);return false; z-table for z-score equivalent percentiles - scroll down to the bottom of link)

Numeric/NVR Z-number

Z = (128-100)/15 = 1.866

A Z of 1.866 gives us 0.9686, which equates to approximately 3.14% scoring higher for that subject area. Approximate Rank Order out of 5574 - 175

PS - Note the above example percentile and rank order is for all cohort, including boys and girls. For Birmingham boys and girls only GS schools, like CHB, the rank order will come down further.

Hope this helps!