Next spring, seniors at about 200 U.S. colleges will take a new test that could prove more important to their future than final exams: an SAT-like assessment that aims to cut through grade-point averages and judge students' real value to employers.

The test, called the Collegiate Learning Assessment, "provides an objective, benchmarked report card for critical thinking skills," said David Pate, dean of the School of Arts and Sciences at St. John Fisher College, a small liberal-arts school near Rochester, N.Y. "The...