What's gotten into Arlene Ackerman?

Philadelphia's superintendent last month ordered teachers to sign an individual contract as required by state law--even though that provision hadn't been enforced for some 25 years. Ackerman was apparently concerned that too many teachers have failed to abide by the requirement (in the contract and in the law) that they give 60 days notice before leaving their jobs. The superintendent got her way, but it was a small skirmish in a much bigger battle Ackerman seems determined to fight.

It looks as if the superintendent is going for an overhaul of the teacher policies that reformers have long said impede Philadelphia's progress. Many of them are in the teachers' contract, now under negotiation and set to expire August 31.

Ackerman, who wasn't particularly associated with teacher quality issues during her six years as head of the San Francisco schools, has said she's impatient with seniority protections that drag out hiring and restrictions on schools picking the teachers they want. She thinks it's too hard to fire ineffective teachers and that the most effective teachers should be paid more.

None of these views wins plaudits from the Philadelphia Federation of Teachers, though the union also worries aloud about being able to find and keep teachers.

The question remains why Ackerman is willing to get tough now on these particular issues.

Is it because her peers in New York, Boston and Chicago--attuned to the national discussion of teacher quality--have succeeded in improving their teacher corps? Is it because Michelle Rhee in D.C. still has the top job despite pushing on some of the same pressure points?

Or could the reason be more local, such as that Ackerman's goals have the very public backing of a coalition of education activists? Or that, following the state takeover of Philadelphia's schools and the rise of nonunionized charters, the PFT's power has been waning?

Then again, maybe Ackerman was alarmed by the data. After a few years of progress in reducing teacher vacancies at the start of school, last year the number of jobs needing filled nearly doubled.