The Post asks: "How is reform to proceed without a better sense of where the problems are?" {"On With the Tests," editorial, June 16}. The answer is, quite simply: testing. Testing in sixth grade, testing in ninth grade and testing again in twelfth grade to obtain a high school diploma.

Since most studies of foreign schools exclude those in Italy, perhaps because Italy is considered inconsequential by American educators, let me tell you how it's done there. Teachers from one school report to another (they are told which school no more than a few days before) when the national exams are administered and proceed to sit in judgment of children taught by their peers. Exams are first written (no multiple choices, only essays, compositions, etc.), and if a student passes the written test he or she is admitted to the oral examinations conducted by other unknown teachers.

This is one way to kill two birds with one stone (better and less sanguinarily expressed in Italian with the equivalent "catching two pigeons with one bean"). And while this system keeps everybody honest, over the years it gives the central authority a pretty good picture of which teacher is succeeding in the endeavor to teach and which isn't.

ELIO E. GRANDI Chevy Chase