So, a student could just watch videos at 2x speed and halve their time spent on lectures….Or, according to the results of other studies reported in the paper, they could watch a video at 2x normal speed twice, and do better on a test than if they’d watched it once at normal speed.

The timing mattered, though: only those who’d watched the 2x video for a second time immediately before a test, rather than right after the first viewing, got this advantage.

The team also explored whether watching the videos at different speeds on separate occasions — initially at normal speed but then at double time, or vice versa — might make a difference to test performance immediately afterwards or a week later.

Though 76% of the participants in this study said they thought watching first at normal speed then rewatching at double time would be best for learning, the order actually made no difference to test results.

The researchers do also add a few caveats. While 2x viewing was fine for learning about the material in their studies — real estate appraisals and the Roman Empire — perhaps it might not work for more complex subject matter;only more research will tell.

But as so many students do report watching at faster than normal speeds anyway, this work is clearly helpful: it suggests that as long as it’s not more than 2x faster, it’s far from being a bad idea.