After Jane and Michael Banks wrote a note detailing all they dreamed of in the perfect nanny, Mary Poppins floated down to their doorstep. And in Howard County's search for a successor to its revered school superintendent, many residents are hoping for the same kind of kismet.

But choosing a replacement for Michael E. Hickey--the dean of Maryland's 24 superintendents and a man granted much of the credit for the system's successes--will be, by all accounts, no easy task.

"It takes an extraordinary person in a very educationally oriented county that can be very demanding," said State Superintendent of Schools Nancy S. Grasmick. "I think it's going to be a tremendous challenge, I really do."

"They would like a perfect superintendent," said Bill Attea, managing partner of Hazard, Young, Attea & Associates, the firm searching for Hickey's replacement. "There is no perfect individual. . . . The demands are high."

Certainly, every system wants the best possible leader. But expectations in Howard--which has the state's highest test scores and yet constantly strives to improve--are even more exacting than normal, according to Attea. Just look at the profile of the type of person the county prefers, compiled by his firm after consultation with the Board of Education, staff and the community:

Someone with a PhD and experience as a teacher, principal and central office administrator.

Someone who reaches out to the community, has worked in a multicultural and high-achieving district like Howard, has raised the performance levels of minority students and is politically shrewd.

Someone who is--to borrow from the profile--articulate, collaborative, firm, fair, friendly, honest, intelligent, motivating, open, open-minded and trustworthy.

Then there are the desires that seem hard to reconcile. The board wants a person who, like Hickey, is young enough to stay at least a decade. Yet they also want someone who already has a long list of accomplishments. (That requirement is tough enough, because most of today's superintendents whoosh in and out of a district within four years or so.)

Board members have said they want someone innovative and creative. But at the same time, they don't want a shake-up, no boot-camp bustle. They think that, for the most part, Howard schools work just fine, and they want a new chief who agrees.

"We are not looking for a Jerry Weast," said board Chairman Karen B. Campbell, referring to the superintendent who marched into Montgomery County this year with a broom, which he has not been shy to use. "We are not looking for someone to clean house, shape up, sweep out. We want someone who will take the helm, steer the course, restudy the maps."

And then there's the shrinking pool of applicants nationwide, which makes finding a good superintendent, like finding good teachers and administrators, difficult even in less attractive districts. "They would like another Mike Hickey 16 years younger," Attea said. "Unfortunately, those people aren't coming into the superintendency."

To figure out what to look for in Howard's next superintendent, the board and the search firm started by assessing what has made Hickey such a treasure in their eyes.

From the moment Hickey, then the superintendent of a suburban Minneapolis district, showed up for his interview in a dapper vest with a red handkerchief peeping from his suit pocket, school insiders saw someone different, someone with flair. (He could be played in the movie by Joe Pesci, if the actor lost some weight.)

Hickey promised to be accessible and to get out of his office frequently, which he did, popping into schools so often that even some students recognize him. He created an extensive system of partnerships with local businesses, so that each school has relationships that provide students with expertise and resources, as well as places in the community to hang their artwork.

Everyone asked about Hickey's accomplishments praised his two long-range strategic plans that set out specific objectives--primarily related to instruction--and guided school employees toward those goals.

A proponent of site-based management, Hickey wiped out two layers between him and the district's 66 principals, so that each reports directly to him, a chain of command unusual among school systems. His philosophy is to hire great people and turn them loose. The move put Hickey, who pays a lot of attention to the details of instruction, in close touch with what happens in classrooms. It also made him more responsible for the principals' failings. (According to many, one of his few weak spots is a loyalty to his principals that even he admitted is sometimes too strong.)

Board members said he is an inspiration--a tactful man who has turned down awards so someone else could have a turn and who taught them to listen better. They also appreciate that the 22 schools built under his command came in on budget, on time.

All told, how much of the success of the Howard County school system--its consistently high test scores, its national reputation, its relatively high morale and satisfaction in the community--can be attributed to Hickey?

"Well, I would say all of it," said school board member Sandra H. French.

Grasmick said, "I think he's brought a lot of innovation to Howard County . . . and that's why they are leading the way."

So it's logical there's some anxiety about the future. And it's also logical that the superintendent is working to alleviate that. In true Hickey fashion--he's big on handing out articles he's clipped--he has given copies of the book "Managing Transitions: Making the Most of Change" to the board and his cabinet.

Before the transition, though, is the "choice," which French called "very daunting." But, as schools spokesman Patti Caplan said, "We have just as much chance of finding God as anyone else does."

Perhaps more.

Attea, from the search firm, said Howard is blessed with a good location, plenty of resources, a national reputation and a supportive board that doesn't micromanage. Even its controversies--such as a current one about inequality in resources and services among the county schools--are minor compared with the squabbles that bedevil other districts, according to state officials.

Despite Howard's high standards, Attea said, he is optimistic the board will be able to hire someone worthy. For example, he said, the county immediately got 50 applications and queries, well over the usual number for such a search.

Hickey, 61, who simply was ready for a change and will assume a chair in educational leadership at Towson University in July, has been begging superintendents he respects to apply. "This would be a real plum," he tells them.

And maybe the right candidate doesn't have to be practically perfect in every way.

Even Hickey was no Mary Poppins at first. "He wasn't this way when he started," French said. "He grew, he evolved, he changed."

CAPTION: Howard County's superintendent, Michael E. Hickey, is leaving after 15 years. School officials fear the effective, well-liked leader will be hard to replace.