I always take notes by hand. I have tried doing on the computer and by hand. By hand is better. There are 2 advantages the way I see it:
1) The motor effects of moving the pen somehow help me remember the information better. It is as if I later remember moving the pen on paper when I have to recall the information. It is very likely that I just trained myself this way over many years.
2) I can sketch. I have a very visual memory and quite often I doodle diagram. Arrows connecting to boxes. A little graph with a relationship can be drawn and visualized very quickly when it might take a whole paragraph to describe.
I have tried a few mind map software and tried doing it with a pen and paper. It works better with pen and paper. With software I often get bogged down in the incidental complexity of using the software itself and it distracts from the actual information.
Mind maps are useful for consolidating and summarizing a large pile of new information. Say the components of an operating system kernel. Or how sorting algorithms works. Stuff like that. Usually with lectures, smaller more focused concepts are presented, so then I still mostly take notes with outlines and diagrams. But when studying for exams, I might letter build a mind-map from the notes.
At some point in high-school I sort of discovered the Buzan (repetitive recall) method on my own. In the Soviet Union, in schools quite often one had oral exams. Where have 100 questions related to anything you learned in the semester or year. And then when you come in, you have to randomly pick from one of the 100 question. Well that means you need to have a mind-map like understanding of pretty much everything. So students studied for the big final test some number of weeks. During those weeks I discovered how certain cyclical summarization and repetition worked best. Also discovered that sugar helps memorize stuff.
I always take notes by hand. I have tried doing on the computer and by hand. By hand is better. There are 2 advantages the way I see it:
1) The motor effects of moving the pen somehow help me remember the information better. It is as if I later remember moving the pen on paper when I have to recall the information. It is very likely that I just trained myself this way over many years.
2) I can sketch. I have a very visual memory and quite often I doodle diagram. Arrows connecting to boxes. A little graph with a relationship can be drawn and visualized very quickly when it might take a whole paragraph to describe.