Think it tends to be mostly a personal preference thing. I use both, but do rather like hierarchies - they just seem like a natural way of grokking things. I a

Think it tends to be mostly a personal preference thing. I use both, but do rather like hierarchies - they just seem like a natural way of grokking things. I also tend to just naturally outline a lot, whether writing, taking notes or coding. Another reason I find them useful is that the act of organizing them is also a form of learning for me - not just the information, but the context and relations. A third reason I like hierarchies is probably a result of a mental flaw. I've always had an issue with "missing words" - where a particular noun just doesn't come to me when I need it. Definitely worse with proper names for some reason. When I'm missing a word, context works much better for finding something.