EMMITSBURG, MD. -- On the tranquil campus of Mount St. Mary's College 65 miles north of Washington, 171 educators, in baggy shorts and Reeboks, are spending most of this week golfing, playing tennis, challenging one another to games of bridge and Trivial Pursuit, and toting ice chests and beverages concealed in brown paper bags to their rooms.

"Who's playing in the {tennis} tournament tomorrow?" Prince George's County Assistant Superintendent Jesse Freeman asked. "I guess I'd better play," answered Potomac High School Principal Sterling Marshall. "I'm so good I must be ranked."

The scene is the Prince George's County Summer Institute for Principals, where 171 school leaders -- their students off visiting relatives, in summer school or at playgrounds and pools -- are getting their own respite for four days this week.

Most know it as "Camp Murphy," the third annual event bearing the name of Superintendent John A. Murphy, who has said having "effective" leaders is a key to success for the area's second-largest school system.

Since Monday, in between the recreational activities, the principals have participated in classroom seminars conducted by outside consultants on subjects such as interpreting test scores, professionalizing the work place, and "How to Market Your School."

They were cajoled and castigated by the consultants and the superintendent. They were patted on the back for the significant gains on standardized tests that the school system enjoyed in the last school year. But they also were told of impending plans to evaluate them more critically.

More importantly, however, they were told of their significance in assuring that the once-maligned school system continues to improve its image and make academic gains.

"There's only one major ingredient that turns a school around, and that's a principal," Murphy told the group early this week.

The camp is organized by the superintendent's office and the seminars are conducted by consultants. Most of Tuesday was spent in classroom lectures. The principals sat at tables and had to raise their hands to ask questions, but they got no homework.

For example, one of the consultants, Dr. Julio George, in a session on professionalizing the work place, asked a classful of principals how many of them had read particular national reports on educational reform. Few hands shot up. "Every hand should be up," George said.

Later, relaxing in his dormitory room-turned-bunkhouse, Murphy explained the increasing emphasis he intends to place on the role of the principal. Murphy said he plans to give principals more flexibility to try projects designed for their individual schools, and hold them, not teachers, directly accountable for students' progress.

"The most critical component is the quality of the instructional leaders at each school," Murphy said. "The principals are key, they're the most important people."

Nationally, studies crediting strong principals with improving the atmosphere as well as academic achievement at their schools have spawned a movement in which the principal's impact on student performance and discipline has overshadowed that of teachers.

Area school systems don't have summer camps, but some typically offer staff development training, lectures, seminars and other workshops for a few of their principals during the school year. Many school systems are beginning to provide additional training, ask principals to hold high expectations for staff and students, involve parents, and become more involved in classroom and instructional concerns.

For example, last school year, District school officials opened the Principal's Center in a renovated school building for lectures and small group seminars. The District's program follows, in part, a corporate leadership model in which principals learn the effective skills of a top business manager.

Frances Collins of Oxon Hill Elementary said the new emphasis on principals encouraged her to assume the job two years ago, after more than 20 years as a teacher. "The principal's role is making sure kids are learning. I'm not just there to manage buildings," Collins said.

The Prince George's camp is paid for by more than $25,000 in private and corporate contributions.

For much of the week the school leaders enjoyed the leisurely pace and the cool Catoctin Mountain breezes, without the traditional campers' complaints of homesickness and bug bites. But some campers did complain about the food.

Laurel High School Principal Thomas Kirby was grateful for the vacation. "A bad day at Camp Murphy," he said, "is better than a good day at work."