Please help me understand [予習]{よ・しゅう}


## tl;dr

The word `予習` is strange to me. Is its usage related to cultural difference?
Does the user's knowledge of the material have something to do with it?

* * *

I've always had trouble understanding what exactly `予習` is, and some of the
definitions I've seen appear contradictory to my American English mind and
words I'm familiar with. Here are some of the definitions I have in various
dictionaries.

### English

>   * Preparation(s) for one's lessons
>

### 日本語

>   * 前もって学習すること
>   * まだならっていないところを前もって学習・練習しておくこと
>

* * *

## Cultural

At first I was thinking maybe this was a cultural difference. I have a hard
time seeing how `予習` is really different (conceptually) from `[復習]{ふく・しゅう,
«さらい»}` ("reviewing"). If today's lesson was on topic X, and tomorrow's lesson
is also on topic X, then the `学習` that I do concerning X in the time between
today's lesson and tomorrow's lesson is just going over information about X
again. To me, it seems pretty straight-forward that this is "review", so I
would use `復習`.

However, if today's lesson was on topic X, but I know tomorrow's lesson will
be about topic Y, saying that I'm going to study up on Y _before_ the teacher
even teaches it to us is not something that _average_ American student would
do. (Note that I use "average student" because a small minority of students in
public schools, or students in elite/private schools may actually do this.
Which may indicate something about our educational system in America...) To
study beforehand about an unlearned topic seems more in line with the east-
Asian (Japan, China, South Korea) mentality where educational discipline is
strict, calculated, and expected. So that's to say that it makes sense to me
that a Japanese student would be expected to study topic Y for tomorrow's
lesson (before the teacher even teaches it), whereas it would be expected that
an American student would be the exact opposite, i.e., if I haven't learned it
yet, I'm gonna play video games/sports/whatever-other-leisure once my homework
and reviews of X are done. So in this sense, `予習` has no relevance in the
(again, average) American educational mindset.

* * *

## Comprehension

When I saw some other definitions for `復習`, I thought the difference between
it and `予習` might be something else. Here is a 国語 definition of `復習`:

>   * 一度習ったことを繰り返して勉強すること
>

Looking at this definition compared to the one for `予習` above, it seems like
more of a difference between things you have learned (一度習ったこと) versus things
you have not yet learned (まだならっていないところ). So if the action is the same
(studying the topic), is the choice between `予習` and `復習` simply a matter of
if you've learned it yet or not? If so, this is easily confusing since I think
most English speakers would use the word "review" to study up on things
they've never learned (possibly for lack of a corresponding word). For
example, if I were taking a trip to a country I've never been to, I would
still say that I'm going to "review" materials (websites, travel books, etc.)
about that country, even though I currently know nothing about it.

So if this is the case, is `予習` more akin to a "pre-review"?

* * *

## What's the verdict?

So is `予習` strange to me because of possible cultural differences? Or is it
about the person's assumed knowledge of the topic? Some combination of the
two? Something else completely?




予習 means "to prepare for a lesson" (see
[here](http://kotobank.jp/jeword/%E4%BA%88%E7%BF%92)). Its opposite is 復習,
meaning "to review", "to rehease" and/or "to practice" what one has learned
([here](http://kotobank.jp/word/%E5%BE%A9%E7%BF%92)).  
The kanji 予, pronounced あらかじめ, means "beforehand", "in advance", or
"previously" ([here](http://kotobank.jp/word/%E4%BA%88?dic=daijisen)). The
second kanji, 習, stands for 習う meaning "to learn"
([here](http://kotobank.jp/word/%E7%BF%92%E3%81%86) meanings 1 and 2).  
予習 and 復習 are widely used in educational setting in Japan. University
curricula must state how much effort is necessary before and after class.

