deal with very advancedtonics limiting the audience to other professors, scientific assistants 248and upper division students. By necessity, the full professor has littleor no time to interact with students on a one-to-one basis. This inter-action is delegated to the scientific assistants (S.A.) who hold the re-citation sessions and consult, generally by appointment, with the indivi-dual student on specific questions. Laboratories are normally conductedby the graduate assistants under the supervision of an S.A. The graduateassistants also grade the laboratory reports. Written examinations areorganized, administered and evaluated by the S.A. with the helo of gra-duate assistants. S.A.'s are also the advisors