Although dozens are vying for Dallas Dance's attention in his first days as Baltimore County school superintendent, he plans to seek out disengaged students and parents of private school students, two groups that he hopes respectively to keep and to attract back into the fold.

On Monday, Dance takes on the job of leading the 105,000-student system, which has grown far more racially diverse and economically stratified in the past decade. The 31-year-old Virginia native seems intent on asking those who are unhappy with the system what he must change to support students on the verge of dropping out and to challenge students whose families have the means to go elsewhere.

"It is a huge county, and it has parts to it that are very different in terms of the socioeconomic situation," said former state school Superintendent Nancy S. Grasmick, who is co-chair of Dance's transition team. While much of the focus in recent years has been on lifting low-performing students, Grasmick said Dance must also ensure "that there is still going to be a provision for very academically talented students."

Almost immediately, he will be confronted with a host of other issues that teachers, parents and legislators say stem from years of poor communication between Superintendent Joe A. Hairston and the public and employees. Staffers no longer trust the central administration because they often received "mixed messages," said Abby Beytin, the head of the teachers union.

"A lot of people have been burned over time. He has to be true to his word," Beytin said of Dance. "He has to build a level of trust. That will be his first and most important battle."

The county system also faces crowded elementary schools, an achievement gap between minorities and white students, and a graduation rate that is dropping.

Dance says he won't announce a long-range plan until February, but he will begin now by attacking the immediate problems, including the switch to a new curriculum, the piloting of a new teacher evaluation system, staffing of schools, and communication. In a recent interview, he said he will look particularly at middle schools, pre-kindergarten education and special education.

Since Hairston took over the schools in 2000, students of color have continued to migrate to the county's schools. Currently, white students are the minority, representing 48 percent of the total enrollment.

The county's students are poorer as well. In 2000, 27 percent of students qualified for a free or subsidized meal; today 44 percent of them do.

The system's test scores have continued to rise, remaining slightly above the state average for nearly all student groups, including special education and minority students. Today, 90 percent of the county's elementary students are passing state tests in reading and 89 percent are passing in math.

Overall, pass rates drop in middle schools, with 72 percent passing math and 83 percent passing reading. Dance, whose last job was leading middle schools in Houston, said he will move ahead with plans that were already under way to restructure four failing middle schools in the county. But he said he will ask the community and his staff to rethink how middle schools might be redesigned to improve student achievement.

"I think we need to look at 'what do middle schools look like in this district,' and it cannot be the status quo," he said.

Not all the statistics have improved in the past decade. Scores for African-American and special education students are far below those of white and Asian students, and despite efforts to improve minority learning, the achievement gap has persisted in the county, as it has in the state.

Although its graduation rate for African-American students is one of the best for large school systems in the nation, overall the graduation rate has dropped steadily, from 89.5 percent in 2000 to 83 percent in 2011. And by sheer numbers, more students now drop out of county schools than Baltimore city schools.

About 100 more students a year are taking the SAT than they were four years ago, and the mean composite score for the three tests has dropped to 1458, below the national mean of 1500.

"Because of the wide range of ... school performance levels, the new superintendent must build a consensus around how to fairly address geographic inequities, while ensuring that all students, including the highest-achieving ones, remain constantly challenged," said Jasmine Shriver, a longtime education advocate in the county.

In recent years, parents have grown increasingly angry about problems with aging, overcrowded school buildings, even as they proclaim that they are happy with the education their children are receiving. The county has the second highest percentage of schools without air-conditioning in the state, greater than the percentage in the city.

With 173 schools, the county has tried to address the overcrowding by building and renovating schools. But the improvements have failed to get ahead of the problem, according to parents.

"I think it is amazing how great the education is and how great the teachers are," said Jill Dudley Cohen, the parent of a Pikesville High School student and an alumna of the school. But she said the lack of air-conditioning is making it difficult for students to learn during parts of the year.