This is a rewritten version of this old post.
Motive
Most people want to learn stuff. Some people prioritize learning higher than other people. But what is true for all people, is that they should learn as much as possible in the time they spend on it. This essay is about just that, optimizing learning speed.
The concept of information concentration
Think of a given chemical that is soluble in water. The water can contain more or less of this chemical. We call this the concentration. It is the same way with language and information. Think of language as a way of communicating info. Expresses vary in how much information ‘contain’ (communicate). From this, we can think of the amount of information per unit of language as the information concentration.
Relevant information
There is a lot of information communicated by a stream of language, not all of which we care about. There are two conditions for being relevant information: 1) It must concern the topic in which we are interested. 2) It must be information we do not already possses. In some cases, one is just generally curious, so the first condition may be easily satisfied. In other cases, one seeks information about a very particular topic. One sometimes does read a nonfiction book twice, but usually it is because one did get all of the information from it the first time because one read it too fast or without paying sufficient attention. Let R be the fraction of relevant information to the total amount of information.
Speed of the language stream
The speed of which we are exposed to the language stream varies. In reading, this various with reading speed, which is adjustable to some degree. In listening, it depends if it is live or not. If it isn’t live, then one can perhaps speed up the language stream. For instance, if one is watching a lecture in VLC, one can speed up the playback (this feature is also found in some Youtube videos now, e.g. for Khan Academy). If the speech stream is live, one can perhaps ask the speaker to speak faster. But in many cases this is not possible, such as lectures, or perhaps the person is already at his maximum speed (maximum speed without starting to be incomprehensible to the listener).
There are physical limitations as to how fast things can go. Even given a very low information concentration, sooner or later it does not work to increase the speed of the speech stream. There are limits on how fast speech can be while one still is able to recognize the words. For reading there is a similar limit. It is possible to increase one’s reading speed, especially with training. But there are limits, sooner or later it is simply not possible to recognize the words any faster due to physical limitations of eye movement.
Speed of the information stream
If one combines the two concepts introduced above, speed of language stream and information concentration, one gets the new concept of speed of the information stream. It is the speed by which information is communicated by the language stream. This is generally faster for written language streams, since reading a word is faster than listening to it.
Generally, the higher the speed of the information stream, the smaller a fraction of the information will one acquire. If one is reading very fast, one will miss out on a lot of details. Just how high a fraction of the information is acquired depends on many factors such as intelligence, mastery of the language, tiredness, interest in the topic and so on.
Skipping irrelevant information
Usually, some parts of the information stream will be irrelevant language as defined above. When this happens, we want to skip ahead in the language stream to the next part where it contains relevant information. If the language stream is non-live speech or written, one can generally skip past the irrelevant parts. It depends on whether the irrelevant parts are grouped together. If the speaker/writer just spreads irrelevant info throughout the stream, then it is more difficult to skip the irrelvant parts.
If stream is live (spoken or written), one can generally not skip. Although in some cases e.g. live streaming over the internet/TV, one can stop paying attention to the stream and get back to it when it begins containing relevant information again. If it is a one-to-one conversation, then one can perhaps ask the speaker to skip ahead. This may be considered rude. If it is a one-to-many live speech situation, one can generally not skip past. This is the case with live lectures.
Conceptually, the idea of skipping information is to keep R (the fraction of relevant information) as close to 1 as possible.
Attention span, mental energy, and available time
Some people have a hard time staying focused, that is, how long they can concentrate at a time before needing a break. Let’s call this concentration time.
Some people have inexhaustible amounts of mental energy. They can spend their entire day learning without getting mentally tired. Other people cannot. Let’s call this mental energy.
I imagine that concentration time and mental energy correlate positively, but probably not perfectly. Thus, there are going to be people who can spend practically all day learning as long as it is not in intervals of more than 1 hour. On the other hand, there are going to be people who only have the mental energy to learn for 4 hours a day, but can keep concentration up for 4 hours straight.
Music seems to have some effects on levels of mental energy. Music perhaps works only for when one is reading, although it seems possible that some people could get something out of listening to music while listening to speech as well. I find that I can go on for hours if I listen to the right music. Generally one wants to avoid distracting music. Often this happens when one starts paying attention to the lyrics instead of the language stream. For this reason, I generally prefer music with either no lyrics, or inaudible lyrics. In that way I don’t get distracted.
The relationships between time spent, speed of the language stream, information concentration and mental energy are probably not so straightforward. Perhaps when one is near max speed of acquiring information, the consumption rate of mental energy is higher than if one was learning at 80% speed. Depending on one’s levels of mental energy then, it might be an idea to not work as full speed, but slow down so as to not run out of mental energy during the day.
Time constraints are another issue. If one has close to every hour one is awake, then one should spread out one’s mental energy over the entire day to optimize the information acquired per day. If one only has a few hours a day to learn, learning at max speed will be more important.
Information stream speed and concentration
My thoughts tend to wander. This happens especially when my brain is not working at maximum or close to maximum capacity. When I do, I stop paying attention to the stream of language before me and think of other stuff. In that way, I’m not learning very much from the stream.
For my focus to work efficiently, I need to avoid language streams with too low information density. For this reason, I almost never use spoken language because I cannot effectively vary the speed so as to match the information stream speed that I want.
Self-control and distractions
People differ in their levels of self-control. In regards to learning, a relevant aspect is the ability to avoid getting distracted by other things. Most relevant today is perhaps the ability to avoid spending many hours talking about irrelevant matters on instant messengers, and not spending a lot of time on social media sites (Facebook, Google+, Twitter) or other similar sites (reddit, 4chan, 9gag).
People who have poor self-control may need to take measures to avoid falling prey to such temptations. Perhaps a good idea is to not read on a computer where there is a browser ready nearby that can take one to one of the sites mentioned before. I do most of my serious reading on a tablet in my bed, where there are fewer distractions. You may need to log off instant messengers, turn off the phone etc. to avoid distractions.
If you are not getting things done, you may need to sit down and think about how you want to structure your learning. Many people have trouble concentrating at home. In that case, it may help to go to a local library. If learning is important to you, you should find ways to optimize it. Perhaps this involves turning off the computer.
If you own a TV, you should sell it immediately. TVs are a waste of time.
Lectures and study groups
To put things together. We want to avoid irrelevant information. This is important when choosing which source to learn from. Lectures are generally not a good way of learning, so avoid them if possible. If not possible, then spend time at lectures reading. This may involve drowning out the noise of the lecture with music in a headset. I have done this extensively for lectures at high school and university, with and without music.
If one still wants to watch lectures, even socially, then it might still be an idea to stay at home. This is because the teachers vary in their teaching abilities as well. So, perhaps one can find better lectures on the same subject on the internet and watch those instead. If one can, then one can perhaps arrange a study group at home where one watches the lectures. This way one can also skip stuff that isn’t relevant if that is true for everybody in the group.
Since people vary so much in intelligence, learning speed, mental energy etc., it may be a good idea to learn by yourself instead of using study groups. If you have to use a study group, make sure to end up in one with people with a similar desire to learn as you have.