It's the principal of the thing

If one were to put elementary school principals in the United States in one room, these are the characteristics that would prevail: * The median age is 46.

* 82 percent are men; 18 percent, women.

* 9 out of 10 are married.

* Fewer than 1 in 10 are members of minority groups.

* 96.4 percent hold master's degrees or higher.

* Three-fourths feel very secure in their job.

* They have been principals for an average of 10 years.

* The average salary is $21,500 for an 11- month work year.

This 10-year study was completed recently by the National Association of Elementary School Principals, the fifth in a series that began in 1928.

The principals' main problems are in dismissing teachers who are incompetent and in managing students who are disruptive. Principals generally find that student behavior is worse than 10 years ago, and they label it a "serious" problem.