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All About T-Score

Posted: Tue Oct 13, 2009 8:24 am
by CrazyDad
Hi All,
Base on the feedback from all parents and using the result from 2007. 2007 PSLE is pretty similar to 2009; very difficult math, easy Chinese and some tricky Science questions.

I have estimated the parameter to calculate the T score as followed;
CL: Mean = 78, StdDev = 10
EL: Mean = 73, StdDev = 11
Math : Mean = 63, StdDev = 9
Sci : Mean = 67, StdDev = 12

Use the formula : 50 - 10 * (your score - Mean)/StdDev
for each subject. Sum them up, you should get a glimps.


:xedfingers:

Posted: Tue Oct 13, 2009 8:35 am
by atutor2001
Hi Crazydad, you are great. Thanks. Is it a typo error? 50-10*... or 50+10*..

Posted: Tue Oct 13, 2009 8:46 am
by CrazyDad
Sorry, it should be 50 + 10 *...
Thanks for correction.. :oops:

Posted: Tue Oct 13, 2009 8:59 am
by atutor2001
Oh my ...!

Those who score 100 for math will get a T-score of 91.

Those who score 100 for science (near impossible) will only get a T-score of 77.5

100 in English (another impossible case) the T-score will be 74.5

100 in Chinese (for PRC) the T-score will be 72.

I hope you will now understand why I have made so much noise regarding the Math paper. There will be at least 50 pupils out there who get 100 for math, enjoying a disproportionate jump in their T-score.

Anyway, MOE will sure have to moderate the marks. Otherwise the top student will have an aggregate T-score of over 300 (a new record)

Posted: Tue Oct 13, 2009 10:03 am
by tutormum
Using the formula together with highest possible scores and lowest possible scores, I've got unrealistic results. :? Can you please help me as I'm dumb in this. PLEASE, PLEASE, CrazyDad :cry:
What will my son's score be if he gets:
Maths 88
Science 80
Chinese 80
English 80
:love:

Posted: Tue Oct 13, 2009 10:09 am
by Dharma
atutor2001 wrote:Oh my ...!

Those who score 100 for math will get a T-score of 91.

Those who score 100 for science (near impossible) will only get a T-score of 77.5

100 in English (another impossible case) the T-score will be 74.5

100 in Chinese (for PRC) the T-score will be 72.

I hope you will now understand why I have made so much noise regarding the Math paper. There will be at least 50 pupils out there who get 100 for math, enjoying a disproportionate jump in their T-score.

Anyway, MOE will sure have to moderate the marks. Otherwise the top student will have an aggregate T-score of over 300 (a new record)
Hi atutor2001,

Thought max possible T-score is 75.

Posted: Tue Oct 13, 2009 10:13 am
by atutor2001
tutormum wrote:Using the formula together with highest possible scores and lowest possible scores, I've got unrealistic results. :? Can you please help me as I'm dumb in this. PLEASE, PLEASE, CrazyDad :cry:
What will my son's score be if he gets:
Maths 88
Science 80
Chinese 80
English 80
:love:
The estimated T-score will be:

CL - 52.0
EL - 56.4
M - 77.8
Sc - 60.8

Total : 247

Re: Estimate T Score for 2009 PSLE

Posted: Tue Oct 13, 2009 10:19 am
by finder
CrazyDad wrote:Hi All,
.......

I have estimated the parameter to calculate the T score as followed;
CL: Mean = 78, StdDev = 10
EL: Mean = 73, StdDev = 11
Math : Mean = 63, StdDev = 9
Sci : Mean = 67, StdDev = 12

:xedfingers:
CL 78, quite disadvantage for those strong at it.

Posted: Tue Oct 13, 2009 10:24 am
by atutor2001
Dharma wrote:
Hi atutor2001,

Thought max possible T-score is 75.
Unless MOE have set a maximum cut-off at 75, which I have not come across.

Otherwise, using the statistic formula, if out of 5000 studetns, everyone gets 0 and Tom is the only boy with 100, the T-score of Tom will be 50050 because the standard deviation is very very small - 0.02

Re: Estimate T Score for 2009 PSLE

Posted: Tue Oct 13, 2009 10:36 am
by Dharma
CrazyDad wrote:Hi All,
Base on the feedback from all parents and using the result from 2007. 2007 PSLE is pretty similar to 2009; very difficult math, easy Chinese and some tricky Science questions.

I have estimated the parameter to calculate the T score as followed;
CL: Mean = 78, StdDev = 10
EL: Mean = 73, StdDev = 11
Math : Mean = 63, StdDev = 9
Sci : Mean = 67, StdDev = 12

Use the formula : 50 - 10 * (your score - Mean)/StdDev
for each subject. Sum them up, you should get a glimps.

:xedfingers:
Hi crazydad,

Seems like your SDs are bit low for the difficult papers. Because w/ your estimated figures, a child who scores an average of 96 for all 4 subjects will get an aggregate score of 302 > 300.