2012 PSLE Discussions and Strategy

[fifiyeo]

mummy so kiasu:

Can anyone explain how does SD affect one's T score? Does higher SD contributes to a higher T score?

Still a bit disorientated. What is SD?

[mummy so kiasu]

fifiyeo:

mummy so kiasu:

Can anyone explain how does SD affect one's T score? Does higher SD contributes to a higher T score?

Still a bit disorientated. What is SD?

Standard Deviation, which is the spread of marks around the average mark. It can be found on the formula of T score calculation.

[elkniwt]

mummy so kiasu:

Can anyone explain how does SD affect one's T score? Does higher SD contributes to a higher T score?

Hi mummy so kiasu,

The formula for T Score is 50 + 10*(X-Y)/Z where
X = Child's Marks
Y = Average
Z = Std Deviation

So for e.g., given two subjects with the same average marks and if you child score the same marks for both subjects, then child will get a higher T score for the subject with smaller SD. (Roughly like that ... , correct me if I get it wrong ..)

Regards.

[mummy so kiasu]

Hi elkniwt, thanks for your reply. Base on what I have just found out, a low SD indicates that the data points are very close to the mean (average), this usually the case for language papers. Whereas, a high SD indicates that the data points are spread out over a large range of values, this is usually the case for Maths paper. If I am not wrong, if the child gets the same mark for 2 different subjects, the T score for the one with higher SD will be higher. Need someone who knows better to explain & confirm.

[elkniwt]

Hi mummy so kiasu,


If we put in some numbers, it will be easier to see.

Using the formula given T Score = 50 + 10*(X-Y)/Z

Say for example,
Average for both English and Maths = 70
Marks obtained by child for English and Maths = 80
SD for English = 8 and SD for Maths = 16

T Score for English = 50 + 10*(80-70)/8 = 62.5
T Score for Maths = 50 + 10*(80-70)/16 = 56.25

So the subject with a lower SD will have a higher T Score. This is what I think, do correct me if I am wrong.

Regards.

[mummy so kiasu]

Hi elkniwt,


Thanks for your explaination. I think you are right. Any idea how do they determine the SD?

[elkniwt]

mummy so kiasu:

Hi elkniwt,


Thanks for your explaination. I think you are right. Any idea how do they determine the SD?

Take a look at this two links - some information on how to get the SD :
http://drax.hubpages.com/hub/deviation
http://standard-deviation.appspot.com/

[august24]

Some mommies suggested practicing writing compo once a week. May I check do u mark them? How to if we r not expert in the language ourselves? Will it still help if I continue to get him to write? Tq.

[Chenonceau]

august24:

Some mommies suggested practicing writing compo once a week. May I check do u mark them? How to if we r not expert in the language ourselves? Will it still help if I continue to get him to write? Tq.

If you can wait a bit I will do a blogpost on this and link here... I am a bit tied up in the coming week. Will write on this in the week after, and put the link here.

[mummy so kiasu]

elkniwt:

mummy so kiasu:

Hi elkniwt,


Thanks for your explaination. I think you are right. Any idea how do they determine the SD?

Take a look at this two links - some information on how to get the SD :
http://drax.hubpages.com/hub/deviation
http://standard-deviation.appspot.com/

Thanks so much. I have better understanding after going to http://drax.hubpages.com/hub/deviation link. :hugs:
:thankyou: