WCHS score and rank VERSUS CCHS score

[TP123]

I have come to realise that though my DDs score was slightly higher than 2 other girls for CCHS, her rank was lower in WCHS than both of them.

tbh I am not at all upset or disturbed about it as she has done enough to guarantee a place in WCHS and fingers crossed for CCHS. But can anyone think why? The ONLY thing I can think of is that WCHS' weighting on age is higher than for CCHS - as these other two girls are a lot younger than my DD.

Would everyone be happy to share the WCHS score and rank and the CCHS score - so that then the maths experts on this forum can help us find out why and this may help future parents?

If others are willing to share this, then I will post my score anonymously as many friends in real life know my DDs rank and I want to remain anonymous on the forum.

<<note to self: proof read the post before posting! - reason for edit in case anyone else wonders why people edit>>

[ToadMum]

Even though it was the same exam, the populations whose raw scores were standardised for the two schools were not exactly the same. For a start, whereas anyone in catchment for WCHS is eligible to be considered for CCHS, very few in what one might consider the 'normal' hinterland of CCHS would be allowed to be considered for WCHS. Certainly girls in Brentwood / Billericay / Maldon / Colchester and Chelmsford itself are way out of the designated area for WCHS, but will form a large proportion of sitters for CCHS.

Whether CEM would apply different age standardisation to different populations for the same exam is debatable.

[TP123]

Given that the exams were the same, and therefore the raw scores for the CEM exam was the same - how can it be that child A gets a higher standardised score than child B in CCHS; but a lower rank (and therefore assuming lower standardised score) than child B for WCHS?

How?

[ToadMum]

Given that the exams were the same, and therefore the raw scores for the CEM exam was the same - how can it be that child A gets a higher standardised score than child B in CCHS; but a lower rank (and therefore assuming lower standardised score) than child B for WCHS?

How?

Because for the two schools, the populations are not the same, as I tried to explain above. In each case, your DD's raw score is being compared to a different set of raw scores.

The mean raw score - which is accorded the standardised score of 100 - for the WCHS group is calculated just from girls in catchment for WCHS, whereas the mean raw score for CCHS will be calculated from the 'WCHS' girls who also wanted a to try for a place at CCHS, plus all the other girls wanting CCHS. So if the mean raw score achieved for 'just WCHS', say was 120 and the mean raw score achieved for 'some of the WHCS girls plus all the other CCHS hopefuls' was 150, then a mean raw score of e.g. 135 would mean achieving a standardised score above 100 in the consideration for WCHS but below 100 when being considered for CCHS. The actual calculation takes into account how spread out the raw scores are from the mean.

I think some 'WCHS' girls would also be eligible to be considered for Latymer? In this case, the same girl wanting to be considered for a place there could achieve yet another different standardised score, as it would be calculated against a set of raw scores with a different mean and standard deviation.

[Zyka]

[quote][/quote]
Don't forget at WCHS, if two or three DD's gets exactly the same standardised score, the distance from their home address to the school is then used to determine the order of ranking.

[TP123]

Don't forget at WCHS, if two or three DD's gets exactly the same standardised score, the distance from their home address to the school is then used to determine the order of ranking.

Ah....yes....my simple mind understands that. Thank you!