Article Summary: Glass & Kang (2018) Laptops/Phones in the Classroom

*this summary is for an article featured in a Voice of America article that I did an interview for based on my Case for Laptops in the Classroom blog post.


To measure the effect of access to laptops, cell phones, and tablets on student performance in lecture-based classes. Glass and Kang predicted that access to devices would allow students to divide their attention during lecture and hurt their performance on assessments. (For those of you who don’t care about lecture-based classes, stick with it, I’ll connect it back to you at the end).

Study design

Students in sections of a cognitive psychology, lecture-based course were allowed to bring their devices to some class periods but not to others. This is a great design because students are being compared to themselves, not to other students who might have other technology habits. In addition, the researchers weren’t forcing students to use devices, they were allowing them to use devices as they normally would. The other clever aspect of the study design was that they measured performance at two time points, during class on just-presented information and a few weeks later as an exam.


Glass and Kang found no differences in performance based on whether devices were allowed or not for the immediate assessment on just-presented information. This means that regardless of whether students were allowed to use devices, they could answer immediate questions equally well. However, for the delayed assessment, the exam, students performed 5% worse when they were allowed to use devices than when they did not. All of the exam questions were based on content from the textbook, so students who did not attend lecture could still ace the exam. Still, even when students had weeks to study and make up deficits in their knowledge, they performed half a letter grade worse when they were allowed to use devices in class than when they did not.

Why this is important 

Many people have studied and written about whether to allow devices in the classroom. Most people who are opposed to devices in the classroom think that they hurt performance by preventing students from paying attention, but this study suggests that isn’t true. Because there were no differences on the immediate assessment, the results suggest that students who are using devices are still processing the information but not deeply enough to create long-term memories that they can retrieve later. The difference in scores on the exam, despite being able to study for the exam, suggests that students think they know the information better than they do. The devices seem to be disrupting their self-regulation, and students feel good about their learning when they aren’t creating lasting knowledge.

For a lot of people, the debate about whether to allow devices in the classroom might seem frivolous. Technology isn’t optional in a lot of fields (e.g., computer science) or for a lot of students (e.g., students in online environments or with disabilities), and it is essential in a lot of course structures (e.g., discussion-based or activity-based courses). However, I would guess that the findings of this study apply to all of these students as well. It’s easy to get distracted with so many options for entertainment or socializing at your fingers, regardless of the course, meeting, or regular-ol’ work session that you should be attending to. We need to teach students to manage their technology and recognize the unintended consequences of poor device habits.

Glass, A. L., & Kang, M. (2018). Dividing attention in the classroom reduces exam performance. Educational Psychology. doi: 10.1080/01443410.2018.1489046

For more information about the article summary series or more article summary posts, visit the article summary series introduction.

One thought on “Article Summary: Glass & Kang (2018) Laptops/Phones in the Classroom

  1. Pingback: Article Summaries: Series Introduction | Lauren Margulieux

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