I find it interesting how being a valedictorian can mean different things. In Australia, it can be awarded to a student who contributed the most instead. 
That"s very interesting! In America it is whoever has the best grades
That's right! And either way they usually give a valedictory address saying farewell to their classmates. 
Yeah. In my school there was a male and a female one. Do they do that in Australia?
I'm actually not sure. I just know that the traditions that deal with academic graduations differ around the world. 
Do you know of any other differences?
Hmm. I know that in India it is called a convocation instead. 
Interesting! I like all the differences. It helps show the differences in cultures.