Screen time has become one of the biggest debates in education.
Parents are worried about how much time kids spend on devices. Schools are restricting phones. Teachers are seeing the effects of distraction firsthand.
At the exact same time, we’re telling schools they need to prepare students for AI.
So I was interested when Cambridge Public Schools decided to actually study what screen time looked like across the district.
We recently had Dr. Lee McCanne, Chief Information Officer at Cambridge Public Schools, join us at GoTeacher to talk about what they found.
Cambridge didn’t just look at Chromebook data. The district conducted classroom observations, surveyed 231 educators, held student focus groups, followed students through their school day, and combined all of that with actual device usage data.
The biggest takeaway for me was surprisingly simple:
Knowing how many minutes a student spends on a screen doesn’t tell you whether that time was good or bad.
20 Minutes Can Mean Very Different Things
The actual numbers from Cambridge weren’t as dramatic as I expected.
Lee said Chromebook use in the earliest grades was around 20 minutes, with the overwhelming majority tied to instructional activity.
By grades 10 and 11, it was closer to an hour and 15 minutes.
But those numbers became less interesting once Cambridge started looking inside classrooms.
They found examples of students using Chromebooks during indoor recess. They saw movement breaks that might once have been led by a teacher being delivered through YouTube. They saw technology being used actively in some situations and passively in others.
None of those things are inherently bad.
But they led to a much better question:
What did the screen replace?
If a student spends 20 minutes on an educational application during recess, the analytics might categorize that as productive.
But maybe those 20 minutes replaced talking with friends, playing a game, being creative, or simply being bored for a while.
The data can’t tell you that.
Lee described it as the opportunity cost of technology.
I think that’s a useful way for schools to think about screen time.
Cambridge Needed Data and Humans
This was the part of Cambridge’s approach that I found most valuable.
GoTeacher helped the district understand what was happening on Chromebooks: usage by grade level, applications, categories, and patterns over time.
But Lee was very clear that the analytics weren’t enough.
“The quantitative data in and of itself didn’t show us the big picture.”
The classroom observations and conversations explained what the numbers couldn’t.
At the same time, the reverse was also true.
A teacher might have one perception of how much technology students were using. Students might have another. Actual usage data gave Cambridge a baseline against which those perceptions could be tested.
The numbers told Cambridge what was happening. People helped explain why.
You don’t need an 80-page research project to borrow that idea.
Look at your technology usage. Then walk into classrooms. Talk to teachers. Talk to students.
Ask what the technology is replacing and whether it’s actually making the experience better.
That’s already a much more useful screen-time audit than calculating a district-wide average.
Then AI Makes Everything More Complicated
The timing of Cambridge’s study is interesting because schools aren’t moving toward a less digital world.
They’re moving directly into AI.
Lee raised a concern I think schools will be wrestling with for years: when does technology extend a student’s thinking, and when does it replace the thinking we’re trying to develop?
An AI tool helping a multilingual student access material can be incredibly valuable.
An AI tool doing the reasoning for a student who hasn’t learned how to reason through the problem themselves is something very different.
That distinction is especially important for younger students.
Cambridge is now thinking about how AI use should change by age, while also investing in media literacy, digital literacy, and eventually AI literacy.
The objective isn’t to keep students away from technology.
It’s to make sure the technology earns its place in the learning experience.
Maybe That’s the Standard We Need
Cambridge isn’t coming out of this study saying every student should be below some universal number of minutes.
Instead, the district is thinking about guidelines for high-quality technology use.
I like that framing much more.
Sometimes the Chromebook is clearly the better tool.
Sometimes AI will allow a student to do something that wasn’t possible before.
And sometimes the better technology is a pencil, a conversation, or going outside for recess.
We shouldn’t use technology simply because it’s available.
We should be able to explain why it’s making the experience better.
That feels like a much healthier standard for screen time, especially as AI makes the line between learning with technology and letting technology do the learning increasingly difficult to see.
