If you needed information about a scientificconcept, whom would you ask? check all thatapply. my teachermy parentsa university professora scientistmy friendsa librarian

It's possible that you could get the information you need from ANY of them. 
But it's true that if you need the info in a hurry, and it absolutely positively
has to be correct, then you should approach them in kind of the order of
what the probability is that you'll get the straight, correct story.

To me, here's how I would line them up in the order of probability:

Tops:  a scientist specializing in that particular field
next    a scientist specializing in a different field
next    a university professor who teaches that particular field
next    a university professor who teaches a different field
next    a librarian, who may not know it but definitely knows where to find it  
next    my parents
next    my teacher
last     my friends  (nothing against my friends, but if it has to be fast
                             and accurate, then I may not have the time to wait
                             for my friend to find it, or the time to check it out
                             after I get it from my friend)