On a normal day, Kojo Hakam would be in a classroom teaching Mandarin to middle schoolers in the Portland public school system. But these aren’t normal days: The entire state of Oregon has shuttered its public schools to help fight the spread of the coronavirus. Thirty-three U.S. states have also closed their schools, along with more than 1,000 universities from the University of California to Harvard. Globally, classes have been cancelled from Japan to Colombia so far, with more certainly to come.

Like many others, some Portland schools will transition to online learning. But Hakam still isn’t quite sure how well that will work for his classes. “There are a lot of things you can’t replace,” he says. “Face-to-face interaction and peer-to-peer interaction—it’s very student-centered teaching.”

Hakam is better off than some teachers. Both he and his students are already experienced with some online tools, such as using Google Classroom to turn in homework. Many other educators—and even entire school districts caught in the coronavirus pandemic—will be using e-learning tools for the first time. According to a survey, more than 16% of college faculty haven’t used basic distance-learning tools at all over the past year, and another 12% say they’re not very proficient with them.

But in the absence of brick-and-mortar schools, online learning companies are stepping up. The startup Coursera is providing free course materials to universities worldwide through July 2020. Higher-ed publisher Wiley is making its WileyPLUS online learning platform and other resources free for the remainder of the spring term. A raft of smaller e-learning services, including Amesite, Cengage, and Study.com, are also making free resources available.

The obvious hope is that some educators using these tools during the crisis will continue using them after it's over. “I don’t want to be excited about a global tragedy,” says Matthew Leavy, a vice president at Wiley. “But I think this is an opportunity to demonstrate the value of online learning.”

An impersonal touch

Ed-tech companies may be looking for a silver lining in the coronavirus economy, but long term it's widespread adoption that they're seeking. However, in conversations with nearly a dozen teachers and education experts, Fortune found widespread uncertainty about the consequences of a rushed transition to online learning. A fundamental issue cited by a significant amount of research is whether delivering an education entirely online can ever be as effective as classroom instruction.

"Students were worse off, especially students starting off the semester poorly prepared, academically," says Eric Taylor, a professor at Harvard's Graduate School of Education who coauthored a 2017 study of online college classes. Taylor's research found students in a virtual classroom got worse grades and were more likely to drop out than those receiving in-person instruction. Taylor notes that the study looked at carefully designed online offerings, while the millions of students about to go online due to coronavirus are more likely to receive fairly improvised programs.

There's also reason for concern in the secondary and elementary school context. A 2016 study by the University of Chicago compared the results of struggling ninth-grade algebra students who took remedial classes online and in person. Children assigned randomly to the online version had lower test scores, worse grades, and a more negative attitude about math than those assigned to classrooms. A 2019 study out of George Mason University and Skidmore College also found that fully online courses left students less prepared than in-person classes and were rarely worth the investment.

But the amount of research into online learning outcomes is substantial, with some studies showing positive effects under certain conditions. Susan Grajek, vice president for communities and research at ed-tech professional organization Educause, argues that in studies showing disappointing results, "we often find that the full range of opportunities offered by online learning have not been utilized." And Wylie's Leavy points out that online learning is more "globally accessible both in reach and affordability" than traditional classroom learning. In other words, at the very least, online courses are better than no classes at all.

Key to understanding the possible problems of online learning is bandwidth. All forms of communication—not just Internet cables—have limits on how fast information can be transmitted. In-person interaction, thanks to cues like facial expression and eye contact, is more interactive and information-rich than online education. Noticing when a student needs extra help is easier in a classroom than on an online discussion board, notes Hakam.

In addition to physical cues, online learning also lacks a social scene, which may not seem important but is vital in schools. “That’s why students sit in the same place most days,” says Dan Faltesek, coordinator of the New Media Communications program at Oregon State University. “They see their friends. But with online classes, there’s no emotional engagement... There’s so little bandwidth that they drift apart."

These shortcomings put more pressure on teachers, says Faltesek, who has developed online courses and teaches them regularly. Teachers are “going to be doing the work of adding bandwidth to every communication,” he says, partly through “much more intensive one-on-one communication with every student.”

The bottom line for teachers, he says: “It is harder.”

Education’s crash diet

The problems described by experts may become even more prominent in a rushed transition to online learning, the likes of which tens of millions of students are now experiencing. “The analogy that comes to mind is going on a crash diet, versus making careful, incremental adjustments,” says Grajek of Educause. "Suddenly, we're making this big shift."

Just as crash diets risk a variety of harmful side effects, a rushed transition to e-learning could have the contrary effect of producing frustration and disappointment for teachers and students using distance-learning tools for the first time. That would be bad news for the educational technology sector overall, which attracted a record $1.9 billion in venture capital in 2019. Coursera alone has raised more than $313 million in venture funding and was reportedly valued at north of $1 billion in April 2019. Wiley is publicly traded and currently valued at more than $1.8 billion.

As mature and full of potential as these efforts have become, this moment will truly put online education to the test. “My advice would be, adjust your expectations downward," Grajek cautions. "We’re all going to be less productive and more distracted in these coming months than we ever were.”

Meanwhile Faltesek sees the benefits of online tools—particularly for making education more affordable and accessible—but he thinks the crisis is more likely to expose the limits of online learning than to trigger a long-term exodus from the classroom.

“This is a moment when we’ll see the value of human connection,” he says, “for cultivating human reflectivity, and human thought.”