WASHINGTON - By the start of next school year, the federal government plans to rate colleges on access, affordability and student outcomes - possibly relying on graduates' employment and earnings data.

Schools could be rated as high performers, low performers or "in the middle," according to a "draft framework" of the ratings plan that the Obama administration is releasing Friday. The document, essentially a status report on an initiative President Obama announced in August 2013, leaves many questions unanswered. But it makes clear that the Education Department intends to assume a new role as arbiter of the performance of thousands of colleges and universities.

"Designing a new college ratings system is an important step in improving transparency, accountability, and equity in higher education," said Ted Mitchell, undersecretary of education. "The public should know how students fare at institutions receiving federal student aid, and this performance should be considered when we assess our investments and set priorities."

Mitchell acknowledged Thursday that the department is deliberating key issues: Which metrics will be used? How will colleges be grouped for comparison? How will they be given credit for improvement? What does "in the middle" mean, the middle 50 percent or the middle 90 percent? Will each college receive a single composite rating, multiple ratings - or both?

The administration is seeking public input by Feb. 17 on several potential metrics it could use to rate schools.

On accessibility, it is weighing the share of students who have enough financial need to qualify for federal Pell Grants; the pattern of expected family contributions to tuition; the distribution of students in groupings by family income; and the share of students whose parents did not attend college.

On affordability, it is considering statistics on average net price and the net price paid by families at various income levels.

On outcomes, it is considering graduation rates, transfer rates [for community colleges], graduate school attendance, loan repayment and "labor market success." The latter, possibly including federal employment and earnings data, could be the most controversial element.

Some higher-education leaders say the very idea of government ratings is flawed.

"What we have repeatedly said is the federal government ought to provide lots of information, but not be in the position of picking winners and losers," said David Warren, president of the National Association of Independent Colleges and Universities.