A greater use of online courses in higher education could end up widening inequalities, rather than narrowing them, according to a new report.
And far more support for students may need to be put in place to make sure online education delivers on its promise.
Online courses have been seen as one way of reducing inequalities, by providing low-cost opportunities for students who might not otherwise be able to afford higher education.
But a new study finds that they may be having the opposite effect, with higher drop-out rates and diminished performance particularly pronounced among groups who already have poorer outcomes, further widening the existing achievement gap.
The report’s authors call for colleges to be more strategic in their course offerings, and provide more student counselling, interpersonal interaction and warning and monitoring of students to try to address these drawbacks.
Online courses are increasingly widespread, with more than three quarters of degree-awarding institutions in the U.S. offering at least one online course by 2016, according to the study, carried out for the American Enterprise Institute.
And one million more students were enrolled in at least one online course in 2016 than in 2012, an increase of 17% over four years.
But the benefits of enrolling in an online rather than a face-to-face course may be exaggerated, according to Di Xu, visiting fellow at the AEI and lead author of the report.
Rather than being a low-cost alternative to face-to-face degrees, online courses actually cost more to develop and run, according to Xu, who is assistant professor of education and social context at the University of California Irvine.
For example, data from the University of North Carolina suggests that the average cost of developing an online course is $5,387, 6% higher than the average for a campus course of $5,103, largely due to the cost of staff or consultants to assist faculty.
The cost of delivering an online course is $17,564, higher than the $16,433 average for a campus course, due to the software and hardware required. Distance courses also tended to have smaller class sizes, 18 compared to 23 for campus courses, due to the amount of work needed to make sure students were engaged online.
But it is in the areas of retention and performance that raise the biggest doubts over the usefulness of online courses.
While some studies show improved performance in online courses over their campus equivalents, Xu finds that many of these were conducted at selective universities among well-prepared students.
Examining the outcomes of online courses across the board reveals a very different picture.
Analysis of a number of studies shows that, "Students in fully online delivery formats had learning outcomes that were substantially worse than those in the face-to-face section of the same course," the report says.
Withdrawal rates are also higher, with students on online courses between three and 15% more likely to drop out, compared with similar students taking campus-based courses.
The report also found there were "strikingly consistent patterns" between course performance and student characteristics over a number of studies, namely that the performance gap between online and campus learning was particularly strong among underrepresented racial minority students, students with lower levels of academic preparation, part-time students and students who did not intend to progress to a four-year institution.
"Since most of these subgroups already tend to have poorer academic outcomes overall, the achievement gaps that existed among these subgroups in face-to-face courses became even more pronounced in online courses," the report says.
Among African American students at California Community Colleges, for example, the average gap in course completion with white students was 13% for face-to-face courses and 18% for online courses.
Among the reasons Xu suggests for the retention and performance gaps are variations in home internet access and differences in levels of self-direction and readiness.
To overcome these obstacles, Xu says colleges need to become more strategic in its course offering, for example by targeting online courses at adult learner who may be more self-directed, and by providing online counselling and tutoring, structured face-to-face sessions and early identification of students at risk of dropping out or performing badly.
