AUGUSTA — A week after heavily criticizing the state’s new A-to-F school grading system, Maine Democrats said they will propose a different way to evaluate Maine’s 600 public schools.

The plan will be introduced at a news conference at 12:30 p.m. Wednesday at the State House. The co-chairs of the Legislature’s Education Committee – Sen. Rebecca Millett, D-Cape Elizabeth, and Rep. Bruce MacDonald, D-Boothbay – are leading the initiative.

They are proposing a concept bill with “at least a dozen” criteria for evaluating schools, said Ericka Dodge, spokeswoman for the Senate Democrats. She said the legislators will solicit input at the local level to come up with the evaluation system.

Critics say the state’s A-to-F grading system, a hallmark of Gov. Paul LePage’s education reform effort, is too simplistic because it’s based largely on standardized test scores in math and English.

It also accounts for students’ growth and progress, and the performance and growth of the bottom 25 percent of students. For high schools, graduation rates are a factor.

More than a dozen other states use similar grading systems. It is the latest education initiative of LePage, who has been sharply critical of public schools.

On Tuesday, LePage’s spokeswoman, Adrienne Bennett, criticized the idea of an alternative plan.

“It’s late in the game to be offering up a completely different system,” Bennett said, noting that LePage first announced the A-to-F grading idea in his State of the State address in January.

“A-to-F is implemented and we’re moving forward,” she said. “The staff at (the Department of Education) and the commissioner are already reaching out to schools that have lower grades and offering assistance.”

Millett and MacDonald did not return calls for comment. Dodge said details of their proposal would be discussed at the news conference Wednesday.

“The proposal develops a fair evaluation system that involves education stakeholders and is based on student progress and local improvement measures,” Dodge wrote in an email.

Education Commissioner Stephen Bowen and others say they intend to use the grades eventually to identify failing schools and provide state money to help them, perhaps through a $3 million “school accountability” fund proposed in the governor’s state budget. That allocation was rejected last month by the Education Committee and is now before the Appropriations Committee.

Bowen said he doesn’t intend to use the grading system to punish lower-performing schools with steps such as reducing funding or taking over failing schools.

LePage’s administration has been criticized for adopting reform measures borrowed from conservative education reformers who advocate changes that include teacher evaluations, school grading systems, voucher programs and charter schools.

Critics say such efforts take resources from the public school system, further burden schools and teachers with new requirements, and unfairly allocate public funds.

Noel K. Gallagher can be reached at 791-6387 or at: ngallagher@pressherald.com