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Science Pracs in general (1 Viewer)

Lazarus

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I'm not wrong. :)

Originally posted by abdooooo!!!
ok explain to me how this work logically without disadvantaging and advantaging a group of canditures.... i need proof before i believe. :)
Your reason for the advantage/disadvantage is:

<blockquote>The raw marks in some courses are much higher/lower than in others.</blockquote>I have said:

<blockquote>All distributions of raw marks are standardised to a common mean, standard deviation and top mark.</blockquote>This means that no course will have much higher/lower raw marks than any other course. Your reason for the apparent advantage/disadvantage no longer stands.

I am happy to answer specific questions, but don't just say "explain the whole thing to me". The mathematics behind it are, in all honesty, extraordinarily complex. As a sidenote, it might be best if this discussion was moved to a more appropriate forum and thread. :)
 

abdooooo!!!

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Originally posted by Lazarus
I'm not wrong. :)

Your reason for the advantage/disadvantage is:

<blockquote>The raw marks in some courses are much higher/lower than in others.</blockquote>I have said:

<blockquote>All distributions of raw marks are standardised to a common mean, standard deviation and top mark.</blockquote>This means that no course will have much higher/lower raw marks than any other course. Your reason for the apparent advantage/disadvantage no longer stands.
yeh i know that... but logically i still can't rationalise it... let me run some models in my head tommorow cause its too late to think now cause i got school tommorow. :(

i'll come back to you tommorow if i still don't get it...

you people are all wrong... the system is flawed. :p
 

t-i-m-m-y

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abdooooo!!!

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Originally posted by Lazarus
This means that no course will have much higher/lower raw marks than any other course. Your reason for the apparent advantage/disadvantage no longer stands.
ok, i had a think of this situation... but how does this work to give a higher average scale for a course if you consider the perfomance for that course its self?

what i mean is if say the 4u math exam this year is really easy so everyone performs well then wouldn't 4u math canditures be advantaged this year compared to last year? since you are counting internal performance... right?

like this chem situation if everyone got good chem notes... everyone will more likely get a better mark then otherwise possible... then does that mean chem scaled average is raised according to the system that you described? but hsc exams vary in terms of difficulty every year... so wouldn't that mean an easier exam will get a higher scaled average?

do you get what i mean? tell me what i gone wrong here? :)
 

Xayma

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Originally posted by abdooooo!!!
what i mean is if say the 4u math exam this year is really easy so everyone performs well then wouldn't 4u math canditures be advantaged this year compared to last year? since you are counting internal performance... right?
If everybody preformed well then it wont affect the scaling much, since in other courses they probably went well.

Originally posted by abdooooo!!!
so wouldn't that mean an easier exam will get a higher scaled average?
Assuming that this years chem scores equaly as well in all other subjects and the only variable was the exam then the scaled mark should be the same.
 

abdooooo!!!

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Originally posted by Xayma
Assuming that this years chem scores equaly as well in all other subjects and the only variable was the exam then the scaled mark should be the same.
thats what i am saying and being argueing about for the whole time... but apparently this is not true according to rage and laz... man im so confused of how this can workout stastistically :confused:

edit: unless i am wrong in assuming that making an exam easy is the same as giving good notes to everyone to help make the exam easy for the students.

Originally posted by Lazarus
There is no such disadvantage. The distributions of raw marks for all courses are standardised to have a common mean, standard deviation and top mark before the scaling procedures are applied. In fact, various modelling experiments have shown that the results of scaling are extraordinarily similar even if this initial standardisation doesn't occur. :) I wonder if I should write a script to simulate it.
so there is apparently no simple logical explaination one could give to rationalise this??? cause i can't see how this can work... in my head anyways... so it can only really be showed experimentally?

but is there any simple explaination you can give for comparing against yourself? ie how do you raise the chem averaged scale by deriving it from the raw of the chem exam???
 
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Xayma

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Originally posted by abdooooo!!!
thats what i am saying and being argueing about for the whole time...
It should be true assuming that all other exam marks are equal (ie even for people who dont do chemistry) since it would indicate that the exam was harder.
 

Lazarus

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Originally posted by abdooooo!!!
what i mean is if say the 4u math exam this year is really easy so everyone performs well then wouldn't 4u math canditures be advantaged this year compared to last year?
No. The 'difficulty' of the exam has nothing to do with scaling - and standardising all marks to a common scale removes any variance in the difficulty of examinations anyway.

Originally posted by abdooooo!!!
since you are counting internal performance... right?
I don't know what you're referring to by 'internal performance' - or, perhaps, more accurately, if you're referring to what I think you're referring to, I have no idea why you're doing so. The moderating process places raw assessment marks on the same scale as raw examination marks. These initial moderated assessment marks can therefore be seen in the same light as raw examination marks. They are averaged with the raw examination marks in order to produce raw HSC marks. Only the raw HSC marks are used in the scaling process.

Originally posted by abdooooo!!!
like this chem situation if everyone got good chem notes... everyone will more likely get a better mark then otherwise possible... then does that mean chem scaled average is raised according to the system that you described?
No, because the improvement applies to the entire candidature for the course. For simplicity, let's say that every single student receives 10 marks higher than they would have had no notes been shared. This doesn't matter, because the relative differences between students haven't changed, and the effect of the 10 mark bonus is removed when marks are standardised anyway.

Originally posted by abdooooo!!!
but hsc exams vary in terms of difficulty every year... so wouldn't that mean an easier exam will get a higher scaled average?
It is true that they vary in terms of difficulty every year. However, as already explained, this has nothing to do with scaling.

Originally posted by Xayma
Assuming that this years chem scores equaly as well in all other subjects and the only variable was the exam then the scaled mark should be the same.
That's correct.

Originally posted by abdooooo!!!
man im so confused of how this can workout stastistically :confused:
Yes, it's very difficult to conceptualise. It is perhaps easier to think of the scaling as being determined by the performance of a candidature over all other courses, but in reality, it is determined by the performance of a candidature over all courses.

Originally posted by abdooooo!!!
edit: unless i am wrong in assuming that making an exam easy is the same as giving good notes to everyone to help make the exam easy for the students.
You are not.

Originally posted by abdooooo!!!
but is there any simple explaination you can give for comparing against yourself? ie how do you raise the chem averaged scale by deriving it from the raw of the chem exam???
You have to remember that there are generally over 18,000 unique combinations of courses every year. There are students in your own courses who are not in your other courses, and who are also taking very different combinations of courses.

The most effective way to augment the scaling for your own courses is to ensure that, on average, the students who take them do well, on average, over all of their courses. 'Doing well' in a course refers not to the attainment of particular marks, but to being placed ahead of other students in terms of relative differences.

Originally posted by Xayma
It should be true assuming that all other exam marks are equal (ie even for people who dont do chemistry) since it would indicate that the exam was harder.
Again, incorrect. See above.
 

abdooooo!!!

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Originally posted by Lazarus
No, because the improvement applies to the entire candidature for the course. For simplicity, let's say that every single student receives 10 marks higher than they would have had no notes been shared. This doesn't matter, because the relative differences between students haven't changed, and the effect of the 10 mark bonus is removed when marks are standardised anyway.
okay this is what i don't get at all... so there are not bonuses in terms of raising the averaged scale for the chem canditure as a whole? can you explain this more clearly... i mean under what circumstances does sharing your notes make it advantages for you to do so, like rage described earlier.

edit: like if i am sharing my notes to help others, what do i get out of it? do this notes have to change the relative differences in the course for me to gain some sought of advantage?
 
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Lazarus

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Originally posted by abdooooo!!!
edit: like if i am sharing my notes to help others, what do i get out of it? do this notes have to change the relative differences in the course for me to gain some sought of advantage?
See this comment:

The most effective way to augment the scaling for your own courses is to ensure that, on average, the students who take them do well, on average, over all of their courses.
You would need to provide notes for most of the courses being taken by most of the students who are also doing your courses. :) (Ideally, all instead of most.) This could be implemented in a number of steps:

1. Get a list of all students who are taking any one of your courses.

2. For each of those students, get a list of all courses they are taking.

3. Combine these course lists and you'll have a list of all of the courses which will influence the scaling of your own courses in some way.

4. Provide notes for all of those courses.

I'll try to give you a very simplified example. You're taking courses C and D. There are students in C who are also taking B, and there are students in D who are also taking E. Further, there are students in B who are also taking A, and students in E who are also taking F.

You would need to help everyone taking any one of B, C, D or E. This would ensure that, in B and E, students taking your courses are ranked above students taking other courses (i.e. A or F).

You can't just help everyone - no rankings or relative differences would change. You're not meant to be able to 'work the system'. And you can see how difficult it would be to do so. :)
 

abdooooo!!!

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no!!! of course i know that. im referring to ragerunners comment about giving away my "chem notes" to help others and benefiting myself in "chemistry" by doing that. how does that work?!?! its not even logically possible, i think... i mean how can you self raise the scale within the course itself... thats what i don't get the whole time and argueing with rage about.


edit: when i say its not even logically possible i mean even if it is possible to self raise the scale within the course itself like you said (if i didn't misintepret you), like i said before it should be mathematically possible to show that this effect is still a disadvantage to you since the people you're helping are likely to be the smart ones, ie the ones that you are directly in competition with and not the idiots who end up getting band ones because they don't come here do they??? lol... i am assuming myself as the smart ones. :p

so what i am saying is this raising average scale of chemistry by giving chem notes is affecting the canditures as a whole, and thus advantages are minimal. while giving notes to other smart people on here is directly disadvantaging myself in terms of the slice of scaled marks i'll get from the course as others will have more chance of getting close or beating me. clearly the disadvantages outweighs the advantages by common sense. :)
 
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Lazarus

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Originally posted by abdooooo!!!
no!!! of course i know that. im referring to ragerunners comment about giving away my "chem notes" to help others and benefiting myself in "chemistry" by doing that. how does that work?!?!
That's right. It doesn't work. :)

Give them to your classmates so you get a better moderated assessment mark.
 

abdooooo!!!

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Originally posted by Lazarus
That's right. It doesn't work. :)

Give them to your classmates so you get a better moderated assessment mark.
yes take that rage... ahahaha... try to trick me to give my notes to bos eh? never?!?! oh no... i've already sent it to you. :(

yes thats my plan, giving all my notes to others at my school after the trials... and lie to them about the hsc now... so it'll make it easier for me in the assessments. hopefully none of them are reading this... :p
 

freaking_out

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Originally posted by abdooooo!!!
yes take that rage... ahahaha... try to trick me to give my notes to bos eh? never?!?! oh no... i've already sent it to you. :(

yes thats my plan, giving all my notes to others at my school after the trials... and lie to them about the hsc now... so it'll make it easier for me in the assessments. hopefully none of them are reading this... :p
thats, what i did after the trials for english- when i knew that i was 5th, i gave my notes to everyone hoping that my assessment mark will not drag me down- but it did though. :mad1:
 

Ragerunner

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If you don't want your notes on BOS then it won't be uploaded.

Up to you.

But btw, nice notes. I think there were some tiny mistakes but don't worry.
 

Xayma

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Originally posted by Lazarus
No, because the improvement applies to the entire candidature for the course. For simplicity, let's say that every single student receives 10 marks higher than they would have had no notes been shared. This doesn't matter, because the relative differences between students haven't changed, and the effect of the 10 mark bonus is removed when marks are standardised anyway.
So is the relative difference worked on marks or by percentage, because if its by percentage it would change eg if someone was to get 1 and another 10, then the second person has 1000% of the first persons score if 10 marks are added this drops dramatically.
 

abdooooo!!!

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Originally posted by Ragerunner
If you don't want your notes on BOS then it won't be uploaded.

Up to you.

But btw, nice notes. I think there were some tiny mistakes but don't worry.
yeah fix the mistakes for me and send it back... ahahaha :p

upload it... i think im confident enough second time around. :)
 

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