I hate it when people make this assumption because for me this is not true. When I take notes I stop comprehending what is being said because the act of transcribing becomes mechanical. I also write slow so I start to lag behind what's being said. Is there any research for this because I would like to be a test subject and prove them wrong.
Sadly, there's very little emphasis on what it means to take good notes, or how to go about doing it. I suspect that good note-takers don't even realize that there's a difference between notes and transcripts, so when they promote note-taking as a study tool they neglect to mention a critical step. You probably could become a good note-taker with some practice, and would benefit from it, but if you're not still in school I doubt it would be worth your time.
When I was forced to take notes I never actually transcribed, but in effect what I wrote down was practically transcribing because I could not keep the processing in real time to write down only the important points.
It takes a few weeks/months to develop your focus, attention span, and memory enough to be able to get near 100% short-term retention, but you start to see benefits almost immediately. And the long-term benefits to your memory and focus can't be understated.
Also, it's really interesting how many other people are expressing that they never took notes in college. I was famous for it in my college (my advisor wrote a paragraph about it in grad school recommendations), whereas I always thought it was common sense, seeing other people who spent the whole class scribbling, but didn't really understand a bit of what was actually taught.
That said, I think pre-studying and post-studying immediately before or after class is really, really helpful - regardless whether notes are taken. The only challenge is that it takes much more time and a lot of effort. This is another clear example of the relationship between effort and reward.
[1]: http://gapingvoid.com/wp-content/uploads/2010/10/rackspace-1...
I've personally found that intensely concentrating on what is said and actively engaging in thinking about it is the most effective way for me to not only remember what is said, but come up with interesting side-thoughts and insights about my own situation in the process.
Writing is just mechanical to me and prevents me from properly concentrating on what is said.
OTOH, at conferences I've been trying to close the laptop and take notes using pen and paper. I get more out of the talks this way, but it works because the information density is lower than my math course.
And I don't take a whole lot of notes, but try to jot down key points or things that might help trigger some recall later. I figure I can Google for stuff if all I have are some keywords written down, so I don't have to notate whole sentences.
This way I have a path to the new information from old information, and I'm unlikely to forget it. For me at least, atoms of information are much harder to remember than connections. And they're much less useful, too.