Freshmen and seniors at about 200 colleges across the U.S. take a little-known test every year to measure how much better they get at learning to think. The results are discouraging.

At more than half of schools, at least a third of seniors were unable to make a cohesive argument, assess the quality of evidence in a document or interpret data in a table, The Wall Street Journal found after reviewing the latest results from dozens of public colleges and universities that gave the exam between 2013 and 2016. (See full results.)

At some of the most prestigious flagship universities, test results indicate the average graduate shows little or no improvement in critical thinking over four years.

Some of the biggest gains occur at smaller colleges where students are less accomplished at arrival but soak up a rigorous, interdisciplinary curriculum.

For prospective students and their parents looking to pick a college, it is almost impossible to figure out which schools help students learn critical thinking, because full results of the standardized test, called the College Learning Assessment Plus, or CLA+, are seldom disclosed to the public. This is true, too, of similar tests.