We don’t know what the university of the future is going to look like.

But Northwestern University, Notre Dame and eight other institutions of higher learning seem a step closer to getting there, and the possibilities are exciting.

On Thursday, the schools announced a new online system that will allow students from one school to take classes at another. And get credit for it.

Many schools already offer online classes to their own students. Others have online offerings for people outside their institutional walls, but not for credit.

Under the new Semester Online program, which will start next fall, a student at Northwestern, say, will be able to take a class at Wake Forest or Duke.

It’s a new approach on this scale, but it won’t be the last attempt to redesign the college years. In a way, colleges and universities struggling with the emergence of online education are like timorous freshmen gazing for the first time at intimidating ivy-covered towers. They know the right path will lead to success, but they’re also worried about failing.

The Semester Online will be open to students anywhere in the world who can meet a host school’s admission requirements, but details remain to be worked out. About 30 courses — probably mostly of the introductory variety — will be offered. They, and the application process, will be announced early next year.

Classes will be covered by regular tuition at member institutions, but outside students will pay about $4,200 to $5,600 per course. Offerings will include lectures by leading professors for 100 to 300 students and online discussions, led by section leaders, for groups of 15 to 20 students. The structure likely will evolve as educators learn along with the students.

“We don’t yet know what works better and what works worse,” Duke Provost Peter Lange said Thursday.