Stanford University ratcheted up interest in online education when a pair of celebrity professors attracted more than 150,000 students from around the world to a noncredit, open enrollment course on artificial intelligence. This development, though, says very little about what role online courses could have as part of standard college instruction. College administrators who dream of emulating this strategy for classes like freshman English would be irresponsible not to consider two serious issues.

First, student attrition rates — around 90 percent for some huge online courses — appear to be a problem even in small-scale online courses when compared with traditional face-to-face classes. Second, courses delivered solely online may be fine for highly skilled, highly motivated people, but they are inappropriate for struggling students who make up a significant portion of college enrollment and who need close contact with instructors to succeed.

Online classes are already common in colleges, and, on the whole, the record is not encouraging. According to Columbia University’s Community College Research Center, for example, about seven million students — about a third of all those enrolled in college — are enrolled in what the center describes as traditional online courses. These typically have about 25 students and are run by professors who often have little interaction with students. Over all, the center has produced nine studies covering hundreds of thousands of classes in two states, Washington and Virginia. The picture the studies offer of the online revolution is distressing.

The research has shown over and over again that community college students who enroll in online courses are significantly more likely to fail or withdraw than those in traditional classes, which means that they spend hard-earned tuition dollars and get nothing in return. Worse still, low-performing students who may be just barely hanging on in traditional classes tend to fall even further behind in online courses.