"You have to say something more than, 'I agree,'" she says. "A substantive post is something that is at least 100 words and furthers the discussion."
In addition to papers and discussion boards, students are often asked to create blogs or projects demonstrating their subject knowledge.
And just because online programs require little face-to-face interaction, that doesn't mean instructors don't require group projects. In those cases, students say they are apt to contact each other through Skype, conference calls or Google Hangouts.
Liu, the Indiana student, says she was surprised by how often she actually heard the voices of her classmates.
"We would email back and forth and then get on a call and I'd think, 'I didn't think you sounded like that,'" she says.
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4. Grading: Although some students might wish otherwise, testing and assessments play a significant role in the virtual classroom. The way instructors grade students varies, experts say. Some will give multiple choice tests graded by the computer, while others will rely more on papers or major projects.
To make sure students don't cheat on exams, Albany's Shea says it's increasingly common for schools to use proctored tests. In some cases, students need to report to a physical location where they will be monitored. On other occasions, students are asked to use a webcam and take a proctored exam at their desk. To make sure the right person is taking the test, students can be asked to flash their photo identification into the camera.
In general, Shea says, instructors familiar with their students' work product are quick to notice when someone might be taking advantage of the system.
"It's actually easy to get to know your students from the quality of work they submit," he says. "In some ways that inhibits breaches of academic integrity."
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