Overall mark scheme?

[angad]

For economics, I understand that the IA and exam are worth 25% and 75% respectively. But how is the final mark derived? If you obtain a 6 on your IA for example, and a 7 on your exam, do they do the following:

Method 1: 0.25*95 (95 is a 6 generally speaking) + 0.75*98 (98 is a 7 generally speaking) = 97.25 which is a 7.

Or

Method 2: If I get 15/20 on my IA (worth 25%), 22/25 on Paper 1 (worth 25%), and 52/60 on Paper 2 (worth 50%), that's 0.75*25+0.88*25+0.87*50 = 84% which falls under the grade boundary of a level 7 (78-100).

I'm asking this because IB tells you the grade boundary for your IA commentaries where 15-16 is a level 6 and 17+ is a level 7 and so on and so forth. But at the same time they provide overall grade boundaries in percentiles that determine your final mark; in which case, what use is are the IA grade boundaries?

[deissi]

From the FAQ:

Calculating your final grade between 1 and 7.

The IB uses a bell curve to find suitable mark boundaries for exams in order to ensure that their level of difficulty will not affect the mark that a student receives. In practice, this means that although students might score poorly on an exam, they might still receive a high mark if the test has been hard for everyone. However, this is not the only factor in setting a grade boundary.

Likewise, if the test has been very easy, a high mark will be required to score a high grade. The system that IB uses to find these boundaries is, as far as I know, undisclosed, and probably far too technical to be discussed here. What can, however, be discussed is the way that your final grade is found from your component grades and your scaled (0-100) mark.

Diploma Programme assessment - Principles and Practices sums the process as follows:

QUOTE

The setting of grade boundaries is... the reconciling of information from different sources: the experienced judgment of senior examiners, statistical comparisons and the expectations of experienced teachers

As mentioned, the final grade will not be found using component grades, but rather component marks. This means that although a student would reach two low 7s in 60% of the assessment, 3 low 6s in the remaining 40% might bring the grade down to a 6. The grade boundary out of 100 can be found as follows:

7 - (lowest grade 7 mark from component 1) + (highest grade 6 mark from component 2) + (highest grade 6 mark from component 3) + (highest grade 6 mark from component 4)

6 - (lowest grade 6 mark from component 1) + (highest grade 5 mark from component 2) + (highest grade 5 mark from component 3) + (highest grade 5 mark from component 4)

I'll illustrate this with an example. The grade boundaries for Finnish A1 SL are as follows:

Paper 1:

7 - 24-25

6 - 22-23

...

Paper 2:

7 - 23-25

6 - 21-22

...

WLA:

7 - 17-20

6 - 15-16

...

IA:

7 - 27-30

6 - 24-26

...

Thus, the aggregate marks required for grade 7 would be:

P1: 24 + P2: 22 + WLA: 16 + IA: 26 = 88

For grade 6:

P1: 22 + P2: 20 + WLA: 14 + IA: 23 = 79.