It's a good 101 technique and worth trying, but I prefer a 102 alternative.

If have enough mindfulness, you start to notice this tension feeling that happens when learning. (I'm not talking about trying to get a project done, getting stuck with a compiler error, then "learning" how to solve it on Stackoverflow. The tension I'm talking about is usually subtle and happens when there isn't some sort of pressing other end goal, just learning to learn for learning and enjoyment.)

This tension is correlated to how well the unconscious mind is digesting what was learned and converting it into long term memory.

If I learn a lot and it is a difficult subject, I might get very tense within 5 minutes of reading. This means I need to take a break to let the mind digest what I just learned.

In the other direction, I can be reading a book and most of it is review, so I feel bored. My initial instinct was to skim to go over it faster, but that only reduces learning. Instead, I can dive into deeper levels of detail, focusing on how the author sees the world, why s/he is demonstrating their findings that particular way, and so on. Basically, diving in more aids learning.

Anyways, sometimes I can go for 2 hours of study straight and be in a happy middle ground of tension where my mind isn't overworked or underworked. This is the ideal state, sometimes called flow. By being mindful of this, my study sessions dynamically adapt to it, into an optimal state of learning.

Also, if it's too tense, I may not be getting it, because there is too much prerequisite material I don't know well. I might turn to wikipedia or other text books at that point. A detour can be fun, and is far better than not understanding the material. I once had to spend 3 full days learning over 20 new concepts (due to recursive prerequisites) just to read a paragraph in a book.

As a participant on HN, what do you think of the pomodoro technique?

I unknowingly used it many years ago to study for the entrance exams for the University. It was just some cute way to keep track of studying that some high school professor described, I didn't even know it had a name. Just tried it for fun.

Definitely works and can help with focus very much, but don't know if it works equally well to types of personality different than mine.

Works for my kid cleaning his room. I view it and focus like weight lifting, you want to build out longer periods of concentration.

Call it will power or whatever, but it's a mental muscle that must be exercised if it is to be realized.