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Twenty minutes into a lecture you realise you have been thinking about a cricket match, and the board is full of equations you do not remember being written. Everyone has this experience, in a classroom or in an online class. This post looks at what researchers found when they measured mind wandering during real lectures, which popular claims about attention do not hold up, and what you can do during and after class.
How often do minds wander in lectures?
Researchers measure mind wandering with "thought probes": at random moments, students are asked whether they were thinking about the lecture or something else. Risko and colleagues (2012) used probes while students watched a recorded lecture, alone or in a classroom. Mind wandering increased as the lecture went on, memory for the material fell, and students who reported more mind wandering remembered less.
It is not just a classroom problem. Using a smartphone app to sample people's thoughts in daily life, Killingsworth and Gilbert (2010) found that people think about something other than what they are doing almost as often as they think about what they are doing, and that this typically made them less happy.
So a wandering mind is normal. The question is what kind of wandering costs you, and what reduces it.
Does it matter whether you drift on purpose?
Yes, according to a study that followed a real course. Wammes and colleagues (2016) probed 154 university students during lectures across a 12-week course. They separated intentional mind wandering, choosing to think about something else, from unintentional mind wandering, drifting without meaning to. Intentional mind wandering was more strongly linked to poorer quiz scores on that day's material. Unintentional mind wandering was more closely related to later exam performance. Mind wandering predicted performance even after accounting for students' grade point average and attendance.
The practical point: the moments when you decide "this part is boring, I'll check my phone" are the ones linked most clearly to lost marks on that material. That is also the kind you can most easily control.
Is attention really gone after ten minutes?
You have probably heard that students can only focus for ten to fifteen minutes. Wilson and Korn (2007) went back to the studies usually cited for this claim, including note-taking studies, classroom observations and physiological measures. They found the research provides little support for a decline at ten to fifteen minutes, and that most studies did not account for differences between students.
A chemistry education study by Bunce, Flens and Neiles (2010) asked students to report attention lapses with clickers during class. Short lapses of a minute or less were more common than long ones, and lapses came in shorter and shorter cycles as the lecture went on. When teachers used clicker questions or demonstrations, students reported fewer lapses, and the effect carried into the lecture that followed.
So attention does not switch off at a fixed minute. It flickers, and anything that asks you to respond pulls it back.
What can you do during a lecture?
Decide in advance not to tune out on purpose. Since intentional drifting was the costlier kind, make a rule: if a part feels slow, use it to tidy your notes or write a question, not to check your phone.
Write questions, not just notes. Every few minutes, jot one question the teacher has just answered. Writing in your own words keeps you responding, the same way clicker questions did.
Notice and return without guilt. When you catch yourself drifting, mark the spot in your notes with a small symbol. Then you know which part to check later.
Predict what comes next. Before the teacher finishes a derivation, guess the next step. Being right or wrong both pull attention back.
Sit where it is easier to engage. Closer to the front, away from friends you will talk to, and with your phone out of reach.
For a fuller set-up for live online classes, see our post on staying focused in online classes.
What should you do after class?
Spend ten minutes on the marked spots. Rewrite each in your own words or work through the step you missed. If a recorded version exists, rewatch only those parts, not the whole lecture. Our guide to learning from video lectures has more on that.
When a gap is in a concept rather than a missing line of notes, go back to the idea itself. The Fermi Concept Library covers every concept in physics, chemistry, biology, mathematics and computing, each with its own lesson, so you can fill the part you missed without waiting for the next class.
In your next lecture, try one thing: each time you notice your mind has drifted, put a small mark in the margin, and count the marks afterwards.
