Signing on to a petition wasn’t enough for some principals across the state who oppose the state’s impending teacher evaluation requirements.

The Long Island principals who launched a policy paper and signature drive against the teacher evaluation system last fall are ramping up their resistance with a lobbying effort. Bringing together colleagues from across the region, including from New York City, the principals plan to take out an ad in the Legislative Gazette, a small Albany publication, asking lawmakers to revise the framework that Gov. Andrew Cuomo has proposed for new teacher and principal evaluations.

The framework that Cuomo proposed was set with the support of the state’s main teachers union, NYSUT, but it doesn’t become law until legislators sign off on it when they set the new budget. That must happen by the end of this month, and until then, legislators could conceivably make revisions.

The principals have broad concerns about the educational value of the evaluation requirements, but they are limiting their ask to three main changes. They want lawmakers to shield teachers’ evaluations from being subject to transparency laws; revise the scoring ranges so teachers whose students do not make academic progress are not automatically rated ineffective; and institute a pilot period before the new system goes statewide.

“This new evaluation system is untested, and needs a pilot time period to try it out, before it is rolled out to every school in the state,” said Nate Dudley, principal of New York City’s Harbor School, in a press release the group distributed today. “The inaccuracies in the recently released city data reports make any new system suspect.”

State officials are already thinking about how to protect teacher ratings from being released through Freedom of Information Law requests, the tool that news organizations used to obtain numerical ratings New York City calculated for some of its teachers. Those ratings were published last month to wide criticism, both about the value of releasing the information and about the validity of the scores, which were subject to wide margins of error and other issues.

Getting legislators to agree to a pilot period and changes to scoring ranges could be tougher to achieve, especially because going to battle with Cuomo over the issues would requiring potentially jeopardizing the entire state budget. Cuomo has placed districts under the gun to put new evaluations in place by the 2012-2013 school year. Plus, state education officials characterized adjustments in the scoring criteria to ensure that teachers whose students make no progress cannot get a passing grade as a major win in the negotiations that culminated in the new framework last month.

More generally, lawmakers are likely to be reluctant about expending political capital on pushing back against a plan that won union approval, particularly as they are taking a stand against a different Cuomo education budget item, a plan to make districts compete for $200 million in state funds.

Today, the group of principals will be meeting on Long Island to plan their campaign. The lobbying effort marks a new phase for their protest, which has gathered support from more than a third of principals across the state and about 10 percent of city principals.