The State Education Department official who has supervised the state’s testing program since 2004 — through skyrocketing scores, a brutal crash, and the dawn of an overhaul — has resigned.

David Abrams, the State Education Department’s assistant commissioner for standards, assessment, and reporting since 2004, announced his resignation today. His resignation is effective immediately, shocking some people who had expected to participate in meetings with him this week.

Abrams’s departure comes at a time of robust efforts to overhaul both state tests and how their scores are used — and of robust criticism of those efforts. Most recently, principals across the state have launched a rebellion against the state’s plan to use student test scores in teacher evaluations. This week, a plan to lengthen reading tests to four hours was released prematurely, then rescinded the next day amid backlash.

The department has yet to find a replacement for Abrams, according to SED spokesman Dennis Tompkins. He said other department officials would fill in for Abrams for now, as would members of a privately funded group that has been advising SED on implementing Race to the Top commitments, which include redesigning student assessments and teacher evaluations.

“Obviously [Abrams] will be missed, but we do have a really strong team that can fill in,” Tompkins said. He declined to comment on the reasons for Abrams’s departure.

Abrams supervised the state’s testing program during a period of controversy and change.

For the first several years of his tenure, test scores skyrocketed, even as experts warned that the tests were not accurate gauges of student performance. In 2010, ex-Commissioner David Steiner, then in his first year as state education chief, acknowledged that the scores were inflated and promised to toughen exams, first in a series of incremental changes and then with entirely new tests in coming years.

Some argued that fundamental improvements to state tests could not happen as long as Abrams remained at the department. Last year, a New York Post editorial pegged Abrams with responsibility for grade inflation on state tests, and Manhattan Institute fellow Sol Stern wrote in the conservative National Review, “It is dismaying to discover that David Abrams, the Albany bureaucrat who was squarely in the middle of the test-inflation scandals of the past few years, is still New York’s state testing director.”

But others saw Abrams as having a role to play in improving the testing program. In the same Post editorial that criticized him, In the editorial, Steiner and Regents Chancellor Merryl Tisch described Abrams as “a valued member of New York’s assessment team.” And an educator who has worked with Abrams on student assessment issues but does not work for the state said today that Abrams is ”very passionate about testing and getting it right.”

Abrams did not respond to requests for comment today.