hey bro long question is all lol
first question
from what I know, the minimum grade threshold for an A in a particular paper is the lowest mark possible to get an A. However, I have sat 2009 May June English First Language, and one of my friends got an A with final mark 87% (if you check the grade thresholds, they come nowhere near 87%). So in saying this, I think the grade thresholds are quite useless as it does not necessarily show the minimum marks for each grade. For the A* is a different story. Even if all your individual papers were A's according to the grade threshold, if you were not ranked in the top 90th percentile, you will not get an A*. There is also , however a contradiction to this. If you check on the Cambridge website, it shows the statistics of each grade for all the subjects in IGCSE for each session. Take Chemistry for example. Approximately 22% of the world gained an A*. This is NOT the 90th percentile (more like 80th) and this leads me to think that everything is dependent on the examiners and how they categorise the candidates' scores. Generally, over 90% u would be looking at an A*, and over 80% would be an A.. I don't think you can go more detailed than that, as grade boundaries change every year.
Second question
quite easier, it means that individual papers cannot be awarded an 'A*'. Individualy, they are able to award A (maximum), and after averaging the scores, if the score is (or what they think is) worthy of an A*, then it is awarded an A*. I thought that half way between 100% and the grade threshold for an A would be the minimum mark for an A*, but as explained above, this is not the case.
Third question
Personally, I am not sure whether 90% or above is ascertained to be an A*. As mentioned above, grade thresholds don't mean much to me as it didn't apply for my last exam.
Fourth question
if by raw mark, you are talking about the actual marks you received in the exam, I am not completely sure. If you take my results for example, on the certificate (not that its an official certificate) it has
subject - First Language English, and MARK RECEIVED- A*(91%)
As you can see, the heading doesn't specify wot exact values were used to calculate the score, and also, my mark is just above 90%, which is thought to be the grade boundary by most people. However, as mentioned before, a friend of mine recieved 87% with an A, so we can conclude that the boundary for an A* is somwhere between the two scores.
My point is, do not rely on grade thresholds to decide whtat grades you will get for what percentage. Cambridge does that for you, so I recommendwaiting until your marks arrive.
Hope that helped.. nd sorry if I didn't answer your question properly, just say which part you still don't get