All About T-Score

[P6boy-dad]

justsay:

[quote]So now you have to use Skewed Gaussian, but by how much.

Hi crazydad , can you help this suaku parent to put it in more layman's term. :oops:

Do you mean first T score formula shall apply using their raw score, then Skewed Gaussian will apply to moderate the T score further if the whole cohort don't do well, the Skewed Gaussian is used to push up the marks of the whole cohort ?

Thank you.[/quote]Statistically, the mean score and the standard deviation are already a moderating tools. What i can say about the T-Score for Chinese (with 80% scoring A and A*) is that, the mean score is VERY high at least 82 and the SD is about 7-8 marks. It means that your child has to score above 82 before he can obtain a T-score of 50 and above. Any marks below the mean score would result in score below 50 for Chinese. I am sure alot of parents dont realise that, thinking that as long as my child score 75 marks would be sufficient. That was why a student who scored 3A* and 1A (chinese) would get a score of 244. The A for Chinese would have given him a T-score of 41 if he scores only 75 marks.

[CrazyDad]

[quote]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:[/quote]For EL and CL, need to divide the total score by 2

Shouldn't the mean for Eng and MT be around 100+ since the total score is 200 respectively?

[CrazyDad]

justsay:

[quote]So now you have to use Skewed Gaussian, but by how much.

Hi crazydad , can you help this suaku parent to put it in more layman's term. :oops:

Do you mean first T score formula shall apply using their raw score, then Skewed Gaussian will apply to moderate the T score further if the whole cohort don't do well, the Skewed Gaussian is used to push up the marks of the whole cohort ?

Thank you.[/quote]Layman Term as followed;

For example, base on CL raw score in 2007, 2% of students has less than 50 mark and 81% of student has more than 75 mark.

if the cohort has 50,000 student, then 1000 student failed and 40,000 student score 75 mark or more. So average point should be close to 80 point right?
And everybody score are around 80, says from 75 to 90 mark. so the spread will be very narrow.

[CrazyDad]

P6boy-dad:

justsay:

[quote]So now you have to use Skewed Gaussian, but by how much.

Hi crazydad , can you help this suaku parent to put it in more layman's term. :oops:

Do you mean first T score formula shall apply using their raw score, then Skewed Gaussian will apply to moderate the T score further if the whole cohort don't do well, the Skewed Gaussian is used to push up the marks of the whole cohort ?

Thank you.

Statistically, the mean score and the standard deviation are already a moderating tools. What i can say about the T-Score for Chinese (with 80% scoring A and A*) is that, the mean score is VERY high at least 82 and the SD is about 7-8 marks. It means that your child has to score above 82 before he can obtain a T-score of 50 and above. Any marks below the mean score would result in score below 50 for Chinese. I am sure alot of parents dont realise that, thinking that as long as my child score 75 marks would be sufficient. That was why a student who scored 3A* and 1A (chinese) would get a score of 244. The A for Chinese would have given him a T-score of 41 if he scores only 75 marks.[/quote]totally agree

[justsay]

CrazyDad:

justsay:

[quote]So now you have to use Skewed Gaussian, but by how much.

Hi crazydad , can you help this suaku parent to put it in more layman's term. :oops:

Do you mean first T score formula shall apply using their raw score, then Skewed Gaussian will apply to moderate the T score further if the whole cohort don't do well, the Skewed Gaussian is used to push up the marks of the whole cohort ?

Thank you.

Layman Term as followed;

For example, base on CL raw score in 2007, 2% of students has less than 50 mark and 81% of student has more than 75 mark.

if the cohort has 50,000 student, then 1000 student failed and 40,000 student score 75 mark or more. So average point should be close to 80 point right?
And everybody score are around 80, says from 75 to 90 mark. so the spread will be very narrow.[/quote]Thanks for the explanation. What I actually want to know more is the Skewed Gaussian. Thanks.... :celebrate:

[CrazyDad]

Vikaesh:

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.

How close will our PSLE results be to the score we get using yr estimations [e.g. plus OR minus 3]





:xedfingers:

:roll: Only time can tell, there are too many unknowns;
1. the actual scores are unknown
2. the parameters estimated base on even more unknown

get the picture?

[CrazyDad]

justsay:

CrazyDad:

[quote=\"justsay\"]

Hi crazydad , can you help this suaku parent to put it in more layman's term. :oops:

Do you mean first T score formula shall apply using their raw score, then Skewed Gaussian will apply to moderate the T score further if the whole cohort don't do well, the Skewed Gaussian is used to push up the marks of the whole cohort ?

Thank you.

Layman Term as followed;

For example, base on CL raw score in 2007, 2% of students has less than 50 mark and 81% of student has more than 75 mark.

if the cohort has 50,000 student, then 1000 student failed and 40,000 student score 75 mark or more. So average point should be close to 80 point right?
And everybody score are around 80, says from 75 to 90 mark. so the spread will be very narrow.

Thanks for the explanation. What I actually want to know more is the Skewed Gaussian. Thanks.... :celebrate:[/quote] Long story...

can check out Wikipedia for the glory details though...

[CrazyDad]

CrazyDad:

justsay:

[quote=\"CrazyDad\"]
Layman Term as followed;

For example, base on CL raw score in 2007, 2% of students has less than 50 mark and 81% of student has more than 75 mark.

if the cohort has 50,000 student, then 1000 student failed and 40,000 student score 75 mark or more. So average point should be close to 80 point right?
And everybody score are around 80, says from 75 to 90 mark. so the spread will be very narrow.

Thanks for the explanation. What I actually want to know more is the Skewed Gaussian. Thanks.... :celebrate:

Long story...

can check out Wikipedia for the glory details though...[/quote]Please go to Wikipedia and search for \"skewed normal distribution\"
:lol:

[Dharma]

atutor2001:

\"How a single subject can change the assessment order of PSLE students\"

OR

\"T-score is not a fair indication of the Students overall performance.

Hi atutor2001,

Frankly, if you ask me the subject that affects the T-score of the pupils most is MT. With such high % of pupils scoring A and A* in MT ranging from 75% to 82%, the average score is likely to be very high probably in the order of 75 to 80 marks. In this case a child who is average in MT but very strong in all other 3 subjects may end up with a very much lower aggregate score than another child who is average at maths but very strong in the other 3 subjects.

The pupils who are strong in all 4 subjects will continue to get high PSLE scores and will be less affected by the performance of the cohort.

We live in an unfair/imperfect world. On whether the system is fair one or not ....I reserve my comments.

[justsay]

[quote]Thanks for the explanation. What I actually want to know more is the Skewed Gaussian. Thanks.... :celebrate:[/quote]
Long story...

can check out Wikipedia for the glory details though...[/quote]

Please go to Wikipedia and search for \"skewed normal distribution\"
:lol:[/quote]

okay...thank you ! :lol: