After only three years at the helm of Harvard’s Graduate School of Education (GSE), Dean Ellen Condliffe Lagemann announced that she will step down at the end of the semester.

Lagemann—whose last five predecessors each served at least eight years—made her announcement in an e-mail to GSE students, faculty, and staff at about 12:40 p.m. today.

After this afternoon’s regularly scheduled GSE faculty meeting, several professors said they were surprised by Lagemann’s announcement.

“The news is new to everyone today,” GSE spokesman Michael Rodman said.

Five of the last six deans of Harvard faculties to step down have announced their decisions at least six months prior to their departure. Lagemann will step down in three months.

Lagemann said that the timing of her announcement makes sense, adding that while she didn’t know the details of other Harvard deans’ departures, her “impression is that March and April is when deans usually step down.”

“You don’t want to be a lame duck for a long period of time,” she said. “You don’t want to do it too precipitously because you want your faculty to make a smooth transition.”

Lagemann, who is the Warren Professor of the History of American Education, said that her decision was based on her desire “to return to writing history.”

Lagemann said she will return to the classroom full-time after taking a one-year sabbatical to write a history book that uses the life of one educator to look at the decline of humanities in education research.

“Frankly, this is a very personal decision,” Lagemann said. “It’s about how I want to spend my life.”

Eliot Professor of Education John B. Willett said after the meeting that the transition from academia to administration can be difficult.

“We’re scholars and teachers and because an administrative role is different you’ve got to learn a new job,” he said. “It’s tough, but it’s a growth experience.”

Willett served as GSE academic dean for two years and acting GSE dean for one year before returning to the classroom full-time.

Lagemann also added that the Allston planning process also factored into her decision to step down. The GSE is slated to move across the Charles River to the University’s new campus in Allston.

“Allston planning is heating up,” Lagemann said. “The person who is in this job after this year will need to stay until Allston gets planned, and that’s longer than I’d want to stay.”