How much do kids learn in college?

For some students, the answer is not that much, according to a new study by researchers at New York University and the University of Virginia.

Sociologists Richard Arum and Josipa Roksa looked at more than 2,300 undergraduates at 24 different schools and found that 45 percent showed no major improvements in areas like critical thinking and writing after two years of college.

The findings are detailed in a new book Academically Adrift: Limited Learning on College Campuses.

The study is based on several data sources including the Collegiate Learning Assessment, a new standardized test. Critics say the test is not a reliable measure of student performance and fails to take into account specialized learning for students who concentrate in particular subject areas.

After four years of college more students showed improvement on the test than after two years, though 35 percent still did not improve.

The study also found that students who study alone learn more than students who study in groups, and Black students were less likely to show improvement on the assessment than their white peers.