Lecture videos are a cornerstone of educational media because there is both real demand for and utility in recording and serving them. But it’s worth asking: Is anyone watching them, or paying attention when they do?

Just like 100-page-long reading assignments, when it comes to long lecture videos it’s easy to expect students just to buckle down and suck it up. The assumption is that streaming the video might even be a bit less painful than sitting through a long lecture in person, stuck on an uncomfortable chair in some big, dark auditorium. While that might be true, it doesn’t address the question of whether students watch all the way through, or do so with enough attentiveness to get anything out of them.

Sure, it’s easiest just to post long videos as is, but does that make sense? Why should we be happy to replicate some of the worst aspects of attending a lecture when we put it online?

Take a look at the “popular right now” videos on YouTube on any given day and you’ll find that most in the top 100 come in under 10 minutes. Even putting aside music videos—which rarely last more than 4 or 5 minutes—you’ll still only find a few that exceed 20 minutes.

One could lament that educators shouldn’t pander to students’ short attention spans, but before doing that, I suggest taking an honest look at our own viewing tendencies. Speaking for myself, I watch comparatively few videos over 10 minutes in length.

Those longer videos I watch tend to be geared toward a “lie-back” experience, such as concerts or long-form dramatic pieces. I certainly have watched some longer lectures, but often while leaving them on in the background as I do dishes or straighten up my office—which is code for “not paying close attention.” Even the ultra-popular TED Talks rarely hit the half-hour mark; most top out at 20 minutes.

Looking at harder data, recent research on student engagement in MOOCs indicates that attention to video taps out pretty quickly. A study of 862 edX courses published in 2014 concluded that 6 minutes is the optimal video length. A more recent study of edX’s four most popular courses showed that half the students stopped watching videos at about the 4-minute mark.

If that data isn’t a wake-up call, I don’t know what is.

Luckily, the solution to the problem of attention attrition is simple: Edit your videos. I’m not saying that you have to turn every 50-minute lecture into a 6-minute supercut (though it’s not a bad idea). Instead, consider breaking down that lecture into smaller, thematically logical parts. Don’t just blindly cut every 6 minutes, but make breaks that fit the flow of the content. That might result in clips that go past the 6-minute mark, but you could also split those into two parts, and simply name them “part 1” and “part 2.”

In addition to increasing the chances students will watch and pay attention to whole videos, you’re also making them more useable. Think of each clip as a chapter in a book that aids a student in finding the topic she most needs help with, or wants to review a second time.

The same advice applies if you’re planning to shoot video lessons. In this case you have control of the content from the beginning and can script out shorter segments.

Now, chunking content into smaller bites doesn’t necessarily mean that you’re assigning students less. Rather, you’re just cutting it into more digestible pieces that increase the likelihood that they’ll complete their assignments. More importantly, you’re also upping the potential that they will retain more, and therefore learn more. Isn’t that what teaching is all about?