BUFFALO, N.Y. — The White House will wade into the controversial business of rating colleges and universities based on their “value,” President Barack Obama announced Thursday as he unveiled a set of proposals aimed at tackling the rising cost of higher education.

The “college scorecard” would help students decide whether a school is worth the hefty tuition bills and help the government decide where to spend federal aid money, while giving image-conscious schools an incentive to keep costs down.

The new system is a notable attempt to influence institutions that are largely out of the federal government’s reach. But the proposals drew criticism as fraught with potential pitfalls and unintended consequences.

Higher education experts worried about the criteria used to devise the ratings and whether the government had reliable data. Some Republicans suggested the administration was moving toward federal regulation or price controls.

The president has repeatedly cited college affordability as a key element of his long-term drive to restore middle-class security. Kicking off a two-day bus tour of colleges in New York and Pennsylvania, Obama said he hoped the rating system would help make college more accessible.

“Higher education is still the best ticket to upward mobility in America,” Obama said, speaking to about 7,000 students at the University of Buffalo. “If we don’t do something about keeping it within reach, it will create problems for economic mobility for generations to come.”

The rating system would be developed in time for the 2015 school year using such metrics as the percentage of students receiving Pell grants (for low-income students), the average student debt incurred by graduates, graduation rates, average tuition and graduate incomes.

Obama will ask Congress to pass legislation giving students at higher-rated colleges larger grants and more affordable loans starting in 2018.

Sandy Baum, an expert on higher education policy and a senior fellow at the George Washington School of Education, called that plan a “very problematic idea.” “It would be very complicated, and it would punish the students for issues that their institutions face,” she said. “It’s hard to see how that would be constructive.”

Obama also called for new incentives to push colleges to adopt programs that could reduce costs — such as offering three-year degrees. He also proposed expanding an income-based student loan debt repayment plan. Currently, only students who took out loans from 2008 to 2011 are eligible for the program, which caps debt payments at 10 percent of income.