[RESOLVED] Finding Rank

[akhileshbc]

Hi guys

First of all my maths is a bit rusty. I can't think of a solution to this simple problem.

I have the following things:

• total score of each student (summed up value of scores in each exam)
• total number of exams

I have to findout the rank of each student based on the above two values.

First I thought about using the average of total score, sorted in descending order as the rankings. But I think, it's not a correct approach to find the ranks.

Any clues on how to find it ?

Thanks in advance

[jemidiah]

Could you give an example of your difficulty?

For instance, if A has a total score of 720 and B has a total score of 630, both having taking the same number of exams, A outranks B. One doesn't even need to take the average, though it doesn't affect the ranking. I don't see why sorting the scores is insufficient.

[szlamany]

You do find the average of each one and then go descending. Make sure that a score of 0 still has a "count up" in the number of exams so the kid takes a hit for that 0

Issue I have to deal with in real world ranks is that if two scores are tied they get the same number but then the next one is ranked as if the duplicate never happened.

Rank 1 - score 100
Rank 2 - score 99
Rank 3 - score 97 - both rank 3
Rank 3 - score 97
Rank 5 - score 95 - back to rank 5

[akhileshbc]

Could you give an example of your difficulty?

For instance, if A has a total score of 720 and B has a total score of 630, both having taking the same number of exams, A outranks B. One doesn't even need to take the average, though it doesn't affect the ranking. I don't see why sorting the scores is insufficient.

Because a student can participate in the same exam more than once. It's kind of mock tests.
Eg:

Student_A -- Exam_E -- Score(50)
Student_A -- Exam_D -- Score(20)
Student_B -- Exam_D -- Score(11)

So, this will become like this:

Student_A -- Score(70) -- NumberOfExams(2) -- Avg(35)
Student_B -- Score(11) -- NumberOfExams(1) -- Avg(11)

Do you think it would be a bad idea to allow students to appear again and again in the same exam ? Now I am getting a feeling like so !

Thanks

[akhileshbc]

You do find the average of each one and then go descending. Make sure that a score of 0 still has a "count up" in the number of exams so the kid takes a hit for that 0

Issue I have to deal with in real world ranks is that if two scores are tied they get the same number but then the next one is ranked as if the duplicate never happened.

Rank 1 - score 100
Rank 2 - score 99
Rank 3 - score 97 - both rank 3
Rank 3 - score 97
Rank 5 - score 95 - back to rank 5

Thanks

[jemidiah]

Because a student can participate in the same exam more than once. It's kind of mock tests.

I would probably take the highest grade the student achieved in the mock tests and ignore the rest, then sort as usual. You could also take the average of the student's mock test scores as you initially suggested; there's no universally best way to do it.

[akhileshbc]

I would probably take the highest grade the student achieved in the mock tests and ignore the rest, then sort as usual. You could also take the average of the student's mock test scores as you initially suggested; there's no universally best way to do it.

Thanks

Then I will go with my present approach.