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Explanation of HSC Marks (Moderating) (1 Viewer)

Dragonmaster262

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Re: Explanation of HSC Marks

For anyone who is still interested, this is online again.

It's crude, but it works.
When I entered in Ragerunner's example marks in that system it gave answers like 69.6 instead of 70 for the bottom mark. It said:

'The bottom mark was adjusted to ensure a monotonically increasing curve.'

What does that mean?
 

Lazarus

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When I entered in Ragerunner's example marks in that system it gave answers like 69.6 instead of 70 for the bottom mark. It said:

'The bottom mark was adjusted to ensure a monotonically increasing curve.'

What does that mean?
The moderating algorithm calculates a conversion curve to convert the raw assessment marks into moderated assessment marks.

The curve is a simple parabola of the form:
[maths]y = ax^2 + bx + c[/maths]​
where 'x' is the raw assessment mark, 'y' is the moderated assessment mark, and the constants 'a', 'b' and 'c' are calculated from the distributions of raw assessment marks and exam marks.

However, it's important that the parabola doesn't have a turning point anywhere within the range of marks that are being moderated, because if it does you can't guarantee that a higher raw mark will always result in a higher moderated mark and vice versa.

If the curve is concave down, raw marks (x-values) beyond the turning point will result in lower moderated marks (y-values) than at or before the turning point, and if the curve is concave up, raw marks (x-values) beyond the turning point will result in higher moderated marks (y-values) than at or before the turning point.

In these situations the rank order of students is changed by the moderating process.

If the algorithm calculates a curve which has that problem, the curve can't be used, so the bottom moderated mark is adjusted to a value which moves the turning point outside the range of marks. Thus within the range of marks for the group being moderated, the curve can be said to be monotonically increasing, as a higher x-value will always produce a higher y-value.

See also: http://en.wikipedia.org/wiki/Monotonic_function
 
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Dragonmaster262

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The moderating algorithm calculates a conversion curve to convert the raw assessment marks into moderated assessment marks.

The curve is a simple parabola of the form:
[maths]y = ax^2 + bx + c[/maths]​
where 'x' is the raw assessment mark, 'y' is the moderated assessment mark, and the constants 'a', 'b' and 'c' are calculated from the distributions of raw assessment marks and exam marks.

However, it's important that the parabola doesn't have a turning point anywhere within the range of marks that are being moderated, because if it does you can't guarantee that a higher raw mark will always result in a higher moderated mark and vice versa.

If the curve is concave down, raw marks (x-values) beyond the turning point will result in lower moderated marks (y-values) than at or before the turning point, and if the curve is concave up, raw marks (x-values) beyond the turning point will result in higher moderated marks (y-values) than at or before the turning point.

In these situations the rank order of students is changed by the moderating process.

If the algorithm calculates a curve which has that problem, the curve can't be used, so the bottom moderated mark is adjusted to a value which moves the turning point outside the range of marks. Thus within the range of marks for the group being moderated, the curve can be said to be monotonically increasing, as a higher x-value will always produce a higher y-value.

See also: Monotonic function - Wikipedia, the free encyclopedia

Are relative differences in Raw Internal Marks always taken into account when moderating Assessment Marks?
 

Lazarus

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Yes, they are taken into account, but they are not always preserved. This is just a side effect of using a quadratic curve to moderate them rather than a straight line (which is only capable of implementing some of the principles underlying the moderating algorithm and not all).
 

elmoateme

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Say in english(advanced), if the top 40 or so kids (out of 180) perform extremely well throughout the year, and in the exam, but the bottom 30 or 40 are absolutely horrendous in both, what effect would that have on all parts of the year i.e. the top, bottom & average students? Would it all cancel out so everything stays relatively the same, or would the marks get stretched in both directions.
 

Lazarus

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If the ranks and relative differences between students are roughly the same in both the internal assessments and the external exams there won't be much of an effect at all.

The moderated marks would be similar to the exam marks.
 

mckensara

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So, your raw HSC marks should increase when they are aligned by BOS?

I am currently ranked 4/44 in modern history, my mark is 87%
i go to a school ranked 18th/17th every year.

should i then be expecting an increase? my marks are stable...
 

Dragonmaster262

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So, your raw HSC marks should increase when they are aligned by BOS?

I am currently ranked 4/44 in modern history, my mark is 87%
i go to a school ranked 18th/17th every year.

should i then be expecting an increase? my marks are stable...
People who tend to score high internal marks tend to score about the same aligned marks. I have no idea why but usually the lower a mark the higher it aligns and vice versa.
 

mckensara

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right okay

i am still a little but confused when it comes to your rank and your actual mark.
We were told at our school your mark was irrelevant, its your rank that matters for internals...
 

Dragonmaster262

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right okay

i am still a little but confused when it comes to your rank and your actual mark.
We were told at our school your mark was irrelevant, its your rank that matters for internals...
Suppose you are ranked first in your school ans these are the top 3 exam marks in your school:

1. 98
2. 94
3. 90

If you are ranked first then your marks in your Record of Achievement will appear as this:

Assessment Mark: 98
Exam Mark: 98
HSC mark: 98

This is because all your school assessment marks get moderated at the end of the year by the Board of Studies. Suppose you are ranked first at your school with an assessment mark of 86 but in the HSC exam you score 96. Then your assessment mark will be moderated to 96. Moderating just matches your assessment mark to your exam mark so if you bomb up in the exam you're gone for good. Using my first example suppose instead you were ranked third in your school but end up with the highest exam mark of 98. Your Record of Achievement will appear as:

Assessment Mark: 90
Exam Mark: 98
HSC Mark: 94

You get 90 as your assessment mark because it is the third highest exam mark in your school and since you're ranked third it's yours.. The Board of Studies are allowed to change your marks but they cannot change your ranks.
 

Aquawhite

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Easiest way to escape the moderation process.

Get first on your internals and then first in the external exam. Problem solved. ^_^
 

natalieloh

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hey.i have one question here.what about if the internal mark is that low while score in the external HSC real exam?? what will the mark be????
 

hello scott

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What about this case? The subject is business studies. The school marks for 1st and 2nd are 73 and 68 but for the predicted external exam marks, 2nd place gets a higher exam mark than 1st with 93 while the student ranked 1st gets an exam mark of 75. Does that mean the moderated exam mark for the student who is 2nd place in school ranking is significantly dropped. Would it be only just above 75.

Thanks in advance for any help.
 

Lazarus

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What about this case? The subject is business studies. The school marks for 1st (A) and 2nd (B) are 73 and 68 but for the predicted external exam marks, 2nd place (B) gets a higher exam mark than 1st (A) with 93 while the student ranked 1st (A) gets an exam mark of 75. Does that mean the moderated exam mark for the student who is 2nd place (B) in school ranking is significantly dropped. Would it be only just above 75.

Thanks in advance for any help.
I have labelled the students in the example above.

If there are only two students in the class, the marks will be as follows:

A

School assessment: 73/100
Examination mark: 75/100
Moderated assessment: 93/100
Final HSC mark: 84/100

B

School assessment: 68/100
Examination mark: 93/100
Moderated assessment: 86.6/100
Final HSC mark: 89.8/100

Note that the moderated assessment for B is 86.6 rather than 75 as would usually be the case.

This is because of the striking difference between their school assessment marks and their examination marks - their assessment marks were very close together and their examination marks were very far apart. There is an exception to the ordinary rule in these circumstances to avoid B receiving a moderated mark that is too low.

If there are more than two students in the class the situation is completely different.
 

hello scott

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I have labelled the students in the example above.

If there are only two students in the class, the marks will be as follows:

A

School assessment: 73/100
Examination mark: 75/100
Moderated assessment: 93/100
Final HSC mark: 84/100

B

School assessment: 68/100
Examination mark: 93/100
Moderated assessment: 86.6/100
Final HSC mark: 89.8/100

Note that the moderated assessment for B is 86.6 rather than 75 as would usually be the case.

This is because of the striking difference between their school assessment marks and their examination marks - their assessment marks were very close together and their examination marks were very far apart. There is an exception to the ordinary rule in these circumstances to avoid B receiving a moderated mark that is too low.

If there are more than two students in the class the situation is completely different.
Thanks heaps.
But I made a big mistake not mentioning that there are 2 others in my class. Yeah, sorry, I suppose I've wasted your time but consider this.

Internal marks
C 67/100
D 50/100 approx

Exam marks
C 70
D 55

In regards to setting the mean of the moderated assessments equal to the mean of exam marks would this really have much effect on me (Student B)? If the gap between C and D in the class marks doesn't change much in the exam marks(and also if there exam marks are higher) this wouldn't have much impact on the moderation that you have already done would it?

THANKS again.
 

Lazarus

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In that situation I would estimate the marks as follows:

A

School assessment: 73/100
Examination mark: 75/100
Moderated assessment: 93/100
Final HSC mark: 84/100

B

School assessment: 68/100
Examination mark: 93/100
Moderated assessment: 76.6/100
Final HSC mark: 84.8/100

C

School assessment: 67/100
Examination mark: 70/100
Moderated assessment: 73.8/100
Final HSC mark: 71.9/100

D

School assessment: 50/100
Examination mark: 55/100
Moderated assessment: 49.6/100
Final HSC mark: 52.3/100

You can boost your moderated assessment mark by helping the other three students in your class maximise their examination marks.

For example, if their examination marks each increased by 5, your moderated assessment increases from 76.6 to 79.7, and if they increased by 10 your moderated assessment increases from 76.6 to 83.3.

Helping your fellow students also assists you to consolidate your learning and maximise your own examination mark.

Once your assessment ranks have been finalised, you're no longer competing against each other - your class is competing against every other class in the state.
 

sirpoopalot7

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Man I still find this confusing. So my drama cohort is pretty strong marks are around this: (overall internal mark)

1: 98
2: 97
3:95
4:92
5:89
6:87
7:85
8:83
9:81
10:80
11:79
12:77
13:75
14:74

I'm around rank 8

What happens if I beat a few people from 7-3? Say this as external mark:

1: 97 (
2: 96
3: 95
4:93
8:92
5:91
6:90
7:89
10:88
11:85
12:85
13:84
14:81

What do you think would be my final mark?
 

A1P

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An old thread but worth reviving to counter the mysteries of Quadratic Interpolation.
Guarantee this will help you understand conceptually how moderation works to transform your Internal mark into Moderated Assessment mark.

(In the context of this post a cohort consists of students from second to 2nd-last ranked. Since 1st ranked gets the top exam mark and last ranked generally gets the bottom exam mark they are not included.)

A fact shown in the BOSTES example but little recognised is
a cohort's Total [Internal Mark after Moderation] equals their Total [Exam Mark]

which leads to this simplified conceptual(*) formula:
=======================================================================
Moderated Assessment = your Internal mark * [cohort's Average Exam mark / cohort's Average Internal mark]
=======================================================================

Read this as: everyone's Internal mark is multiplied up or down by the factor of
[cohort's exam performance] over [their collective internal marks]
eg. cohort averages 60 internal but averages 72 exam your Internal mark is multiplied up with 1.2
otoh if school gives so generous marks that they average 80 internal but 72 exam, your Internal mark is multiplied down with 0.9 (**)

The same formula written in another way
Moderated Assessment mark = [your Internal mark / cohort's Average Internal mark] * cohort's Average Exam mark

illustrates how it's neither your Internal mark's face value nor your rank per se but your Internal mark relative to the cohort's Internal marks that truly matters.

Notes:
(*) As said this is a conceptual but I believe good enough explanation. Your actual Moderated mark may differ a little (perhaps 1-2 marks) due to the quadratic effect of the function used.

(**) I can say this with confidence since this mathematically leads to Total [Moderated Mark] = Total [Exam Mark].

(***) Remember your HSC mark consists 50/50 of your Exam mark + Moderated Assessment mark.
If you score exam say 20 marks higher than internal you benefit 50/50 directly from the 20 extra marks yourself PLUS you share this 20 to the cohort including yourself.
 
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eddydundee

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Hi, my name is Edwin, I would like a rough estimate for my ATAR please

School rank: 167 (2009) and 164 (2010)


Subjects:

1. Standard English: mid 70s (35/154)

2. Business Studies: low 80s (14/76)

3. General Maths: mid 80s (14/125)

4. Senior Science: mid 80s (4/36)

5. Community & Family Studies: mid 70s (16/44)

6. Studies of Religion 1: mid 70s (41/91)

Thank you!
 

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