When it comes to community colleges, one of the concerns always lurking in the back of my mind has been how good a job they do. Of course, their success is uneven—the Pope Center has written about the tremendously talented community college teacher Kelly Markson and about a North Carolina college in turmoil, with claims of racial discrimination and mismanagement of funds.

In spite of this variation (and also a certain lethargy that seems to crop up in community college governance), I have generally felt that because community colleges are close to businesses in their areas, they are practical and down-to-earth and can prepare students for useful jobs.

But a new study says that when it comes to short-term certificates, which are proliferating at community colleges, there is no solid evidence that they help recipients get jobs. The study was conducted by researchers from Columbia University and the California Community Colleges’ Board of Governors.

The Chronicle of Higher Education quotes from the study: “Although we would not go as far as to say that short-term certificates never have any value, the evidence is suggestive that they tend to have minimal value over and above attending college and earning some credits.”

The fact that these colleges are public entities, sometimes run with little oversight, may mean that they, like other institutions of higher education are subject to educational fads, whether successful or not.