As thousands of D.C. students open the security seals on their exam books Monday morning to begin another annual round of standardized tests, they will also launch a critical new chapter in the city’s school reform effort.

In the year since the last citywide testing, the quest to transform the struggling school system has itself undergone a sea change.

A new mayor, the second since schools were placed under executive control in 2007, is trying to regain his political footing after allegations of improper hiring practices. A new acting chancellor is attempting to preserve past gains and pursue new ones with a tightened budget. And the D.C. Comprehensive Assessment System, regarded by officials as the critical metric for assessing academic progress, faces new scrutiny about its accuracy.

A recent National Research Council report strongly cautioned that without more-sophisticated data analysis, it was “naive” to use recent growth in test scores as evidence that mayoral control has led to improved academic achievement. Last week, a USA Today report raised the possibility that some of the growth under former chancellor Michelle A. Rhee was the result of cheating.

The multiple issues have some parents asking: Has D.C. school reform hit a pothole, or a wall?

“It’s embarrassing. You have high hopes — and for this to come out,” said Diane Rawlings, the mother of a seventh-grader at Sousa Middle School in Ward 7, discussing the elevated rates of answer-sheet erasures found at eight schools, including her daughter’s.

Although Rawlings said she doesn’t think there was misconduct at Sousa, her confidence in the future has been shaken by reports that Principal Dwan Jordon, who has led a celebrated turnaround at the school, might be moving on at the end of the academic year. Jordon deflected a request for comment Friday, saying he was focused on this week’s testing.

The history of urban public education is filled with accounts of reform initiatives that began with a burst of energy and urgency, only to be stalled by political reversals, budgetary crunches or turnover in key jobs. Cities such as San Diego and Cleveland offer such narratives.

Some see the District at a similar crossroads.

Members of the senior management team that Rhee formed continue to peel away. General Counsel James Sandman and Anthony Tata, chief operating officer, left earlier this year. Last week, family and community engagement chief Peggy O’Brien announced her resignation. Erin McGoldrick, the District’s head of data and accountability — and a key player in Rhee’s efforts to instill a “data-driven” culture inside the school system — has told officials she will leave this summer.

There are other departures further down the management ladder and whispers of concern that the momentum of change under Acting Chancellor Kaya Henderson may be slowing.

“The sense is that the foot is off the gas,” said one vet­eran administrator, who asked for anonymity because he was not authorized to speak publicly on such matters.

Mayor Vincent C. Gray (D) and Henderson say they have not taken their eyes off their primary objective.

“My commitment to education reform is unshakable, and my goals are clear,” Gray said in his State of the District speech. “A great teacher for every student and a great school for every community. There is no margin for error here.”

Other major players in the local education community also said they do not see the recent turbulence as an obstacle to the long-term goals they share with Gray.

“I still see this as a town that is very hungry for education reform and education improvement,” said D.C. State Board of Education President Ted Trabue.

Ashley Allen, a parent at Mann Elementary in Northwest Washington and a partner at the Endeavor Group, a firm that advises businesses and philanthropies that donate to local education, said the donor community has not lost confidence in Gray or Henderson.

“They’re in this for the long haul,” Allen said. “Education reform is messy, and it takes time and hard work.”

The District’s successful application last year in the federal “Race to the Top” grant competition acknowledged the challenge of extending the progress that began with former mayor Adrian M. Fenty’s takeover of the school system in June 2007.

“Few districts, if any, have managed to sustain the pace of initial (Years 1-3) education reform,” said the document, drafted by Fenty’s staff. “At the very time when reform fatigue becomes a risk, D.C. needs to accelerate efforts to maintain — and grow — its upward trajectory.”

But not everyone agrees that continued acceleration is possible or even desirable.

The high-velocity tenure of Fenty (D) and Rhee brought a game-changing collective bargaining agreement, a rigorous new-teacher evaluation system, a massive round of school closures and record capital investment. But it also left many constituencies bruised by a style that de­emphasized community engagement — a factor widely seen as contributing to Fenty and Rhee’s undoing in 2010.

Many stakeholders are looking for Gray and Henderson to establish a more sustainable middle ground with steady, deliberate progress.

Frederick M. Hess, an education analyst for the conservative-leaning American Enterprise Institute, said that the District’s education story is “certainly evolving” but that the direction remains unclear.

“Whether it involves moving from this incredibly frenetic, intense period to something more sustainable, or [whether] it represents backsliding won’t be clear for a little while yet,” Hess said.

D.C. officials say changes at the national level have established a foundation for sustained local reform. Race to the Top, which will bring $75 million to the city over four years, requires the District to continue much of the work Rhee began, including expanded use of the rigorous teacher evaluation system that ties academic growth to job security and more sophisticated use of data.

Last year, the District joined dozens of states in adopting national standards for what students should learn in English and math through high school, an initiative that will take root within a couple of years. Supporters say it will provide a clear basis for assessing how D.C. students are achieving relative to their peers in other states.

A test security firm hired by the District said it found no evidence of cheating at eight schools flagged for high rates of answer-sheet erasures. But critics say the inquiry by Caveon, based primarily on interviews with teachers and staff members, lacked rigor. The city’s inspector general is reviewing Caveon’s work. At stake is public confidence in the school system’s ability to assess student progress fairly and accurately.

Some regard the erasure issue as a powerful argument for moving away from a focus on test scores toward a more holistic vision of what academic success looks like.

Henderson, Rhee’s former deputy, said she wants to ease a testing regimen that she concedes has left students and school staff “stressed-out and crazy.”

“I think we’ve swung the pendulum from one extreme to the other . . . from absolutely no accountability to uber-accountability,” she said last week at a panel discussion. “I think we’re now finding our way — or we have to find our way — back to some happy medium.”