Does anybody have a good idea as to how I could score multiple skills, and then combine them as a 'top level'-Elo rating?
Use case: I want to rate a student. I give the student 100 English exercises, these exercises are of different types - i.e. 25 grammar exercises, 25 vocabulary exercises, 25 listening exercises, and 25 apprehension exercises.
Then I would like to be able to calculate four individual Elo-ratings, as well as one combined rating that shows how well the student generally is at English.