“If you are finding your students are being distracted on their cellphones or on laptops, you have to ask yourself: What am I doing in my teaching that is not engaging?” she said. “How can I give them opportunities to participate so they don’t feel the need to disappear down the rabbit hole?”

She uses devices in the classroom to create a communication “back channel” with students, often integrated with social media. Students post questions on Twitter for journalists and authors, who respond in real time. Professor Greenhow said students “will find things in the news, in the media, tweet about it in the Twitter back channel, and I will end up projecting those tweets in class,” adding, “I have more insights into my students and what they want to learn more about.”

A study by David Baron, a researcher at the department of chemical engineering of the University of Cape Town in South Africa, and colleagues from the university, published in 2016 in the journal Computers & Education, defined the educational back channel as “software that allows a secondary, digital conversation to take place during a university lecture.” The study found that “a digital back channel increased the overall number of questions asked in a class,” with “little evidence of the back channel promoting distraction in class.”

Perry Samson, a professor in the University of Michigan’s department of climate and space sciences and engineering, developed his own back-channel program for his classes. “Students can click on that, and I’ve got a meter on the room, telling me how many students are confused.”

The app lets students give anonymous feedback answered in real time by teaching assistants as he lectures. Professor Samson also consults with the educational video technology platform company Echo360, which records, streams and captions live academic lectures, among other features. The company placed the back channel he developed into its Active Learning Platform.

These tools also help students who have special needs. Arianna Esposito, the director of life span services and supports for the advocacy group Autism Speaks, says students on the autism spectrum use smartphone-enabled augmented technology and other applications “at a much earlier age than ever before, and as those students age out, and enter college, they have developed new study skills and they have used cognitive behavioral support that helps them be successful in the classroom.”

While Ms. Esposito emphasized that a specific example cannot apply to everyone, useful and readily available smartphone, tablet and laptop features include notes to write out questions before speaking and calendar reminders. She also mentioned universities creating centers to help autistic students, including the Kinney Center at St. Joseph’s University in Philadelphia.