Behind the Back Channel

Perry Samson, an atmospheric science professor at the University of Michigan, noticed that students in his large introductory lecture classes never seemed to have any questions.

“I’d go, ‘Any questions?’ and nobody asked a question. I assumed I’d nailed the lecture and went on,” Samson said.

But Samson suspected some students might be confused after all. He decided to do an experiment. He implemented an anonymous “back channel” for students to ask questions during his meteorology class, using Echo360's video and learning platform. (LectureTools, a company Samson co-founded, was acquired by Echo360 in 2012.) Students could attend lectures in person, where they would be asked to have a laptop or smartphone out, or they could watch a livestream remotely. On the course website, students could submit questions for a teaching assistant to answer. Every student could read the questions submitted and their answers during lecture, but only the assistant and Samson could see who was submitting them.

Samson found that the total number of questions students asked increased tremendously, from about 50 per semester to about 300 to 500 per semester.

“Clearly the students are now asking the questions they wouldn’t [have], so they have the opportunity to clear up misconceptions,” he said. “It’s another mechanism for them to engage with the material.”

Notably, with the addition of the back channel, female students asked as many questions as their male counterparts, even though they reported being less comfortable asking verbal questions at the beginning of the course. For male students, about half said they were uncomfortable asking questions in the class, compared to 62 percent of female students.

Norman Bier, executive director of the Simon Initiative at Carnegie Mellon University, said that the effect of the back channel on these female students is not surprising. Students can often be afraid of doing things in class that they believe make them play into a stereotype, he said. Women taking part in a STEM course, who have been presented with a stereotype that they do not perform well in the subject, might be afraid to ask questions and “reinforce” the generalization. Giving students a way to ask questions without outing their identities could neutralize the threat.

“All of us benefit from the opportunity to ask questions and see the kinds of questions others are asking without feeling like we need to fully put ourselves out there,” Bier said. “To ask a question is to reveal ignorance in some ways, and that’s not always a comfortable experience, no matter how much we want to make it comfortable in a university setting.”

Self-identified first-generation students or nonnative English speakers in the study were no more likely than the rest of the class to be uncomfortable asking questions. Those students asked back-channel questions at about the same rate as the rest of the class. Samson suggested that the lack of discrepancy in comfort level might be due to the experiment’s setting at the University of Michigan, where admission is highly selective.

The experiment did not examine whether the back channel improved student grades over all, but Bier said that getting students to ask questions often does improve their learning.

“We’ve seen just a pile of research suggesting that active learning really is important and creating these kinds of active learning opportunities where we’re directly engaging with the students is something that’s going to lead to conditions for more robust and thoughtful learning generally,” Bier said. “Asking questions and classroom participation can be one form of really pushing on that active learning piece.”

Samson said that although he thinks the findings are strong, there were some experimental controls he was not able to implement. For example, the number of verbal questions asked before the back channel was implemented was not as attentively calculated and was mostly from memory. Assessments in the class did change over the semesters, as did the assistant. Further research, he said, could focus on the quality of the questions and, longitudinally, the back channel’s effect on retention of women and minorities in STEM majors.

Other Applications

Samson said he thinks an anonymous back channel should be standard in all introductory courses, across disciplines. Bier noted that many classroom instructors are using more low-tech approaches, such as clickers or Google Forms, to achieve similar goals.

Michele Barr, a kinesiology lecturer at Fullerton College, conducted an experiment of her own a few years ago using clickers, where she compared how cognitively engaged students were during class and how well they demonstrated critical thinking at the end of a lesson, when they were asked to answer questions anonymously with clickers versus verbally. The response rate to questions, as well as students' critical thinking, both showed improvement with the clickers. The students also reported that they preferred clickers.

“They have this huge fear and anxiety around being embarrassed and being wrong,” she said. “They used words like ‘judged,’ ‘ridiculed,’ ‘humiliated,’ ‘shamed.’” The anonymity likely helped alleviate that fear and also gave students more time to think about questions," she said.

Barr said that she had in the past used a similar tool to Samson’s, with slightly different results. She didn’t have an assistant to answer the questions, so they were displayed and she would answer them verbally as she taught. That implementation, though it worked for her small section, would be overwhelming in a large lecture, she thought.

Bier said that conferences and other spaces have been using technology in similar ways to give participants anonymity. The Global Learning Conference a few years ago, he said, allowed attendees to anonymously ask questions or suggest topics as they were coming in. Those were then displayed publicly.

As far as the dark side of anonymity, Bier said, it can sometimes exacerbate bias, such as in anonymous instructor evaluations that are harsher or less focused on academics for female or nonwhite instructors than their peers. But over all, he said, anonymity can be a positive offering to students. “Getting these techniques out in broader use is important.”