How to evaulate/track subordinate technicians?

I’ve been using RT for years and I’m absolutely thrilled with it.
However, the boss and I are now looking for a way to evaulate the 1st
level techs. (They’re teachers, aids, etc. in our schools, actually.
This is why we need to evaluate their performance as part-time
technicians.)

 In particular, we want to look at their escallation and responce rates. 

We believe that they might be escallating almost everything instead of
doing any work that takes more than 5 minutes. We also suspect that
they’re not checking up on the tickets on a daily basis, as they are
required to do.

 Any suggestions?

 All that I've come up with so far is to add a Custom Field that only the

full time techs (myself and one other guy) can view or modify and then
put “Escallated/shouldn’t”, “Not escallated / should have”, etc. into it.
But this plan still requires us to go through every ticket and evaluate
them. So it feels very inefficient.

 Any help or suggestions or even "RTFM page XX" would be appreciated.

                                                   Thanks in advance,
                                                   Jaime Kikpole

Network Administrator
Cairo-Durham Central School District
http://cns.cairodurham.org