Adapted from my original post at [forum.zettelkasten.de](https://forum.zettelkasten.de/discussion/1072/principle-of-atomicity-file-based-zettelkasten-vs-roam-research#latest)
I’ve been using a zettelkasten (Sublime Zettel) for more than 2 years. It has over 2000 notes in it covering diverse topics from neuroscience to cooking to clinical medicine. It’s worked well, and as it enlarges, I get more value from it. But when new and interesting tools come along, I like to check them out. I know Roam Research has gotten a lot of attention around here and around similar corners of the web. So I started playing with it a few weeks ago.
I think one of the most striking and important differences between Roam and Markdown-based systems is that in Roam, the atomicity is even more granular. The fundamental unit is the bullet or line of text. Every bullet has a unique ID that allows it to be linked to anything else.
In Markdown-based ZKs, like mine, or those that use the Archive, the zettel is a markdown file, which usually has several lines of text in it (and sometimes a lot of text). This is helpful in that it consolidates related sentences but it doesn’t allow the level of granularity that Roam does. Sometimes I really do only want to link to a single sentence and not an entire note. Roam allows that. A markdown-ZK could allow this if one made zettel-files line by line (one line per zettel), but this becomes really tedious, mostly because you have to explicitly title each zettel file.
In contrast, in Roam, you can just open up a Daily Note and start writing. There is no cognitive overhead in having to title a zettel. You can basically do a brain dump and if you didn’t feel like it, you could leave that brain dump right there and never move it or properly place those lines into their own pages (groups of related bullets).
But, then, as Sasha Fast talks, you can build infinite hierarchical “Structure Notes” or whatever you want to call them elsewhere.
So all this to say, I think one of the most enabling features of Roam is the size of the atom can flexibly go from a single line up to whole blocks of hierarchical bullets, without the cognitive overhead of having to create distinctly titled pages.
The other things like the back-linking and all that are cool too, but I think the fact that bullets are the unit of operation is perhaps the most powerful difference. I don’t want to jump onto the Roam Wagon, since it’s proprietary and I like my system, but I’m wondering if I’m losing something by sticking to the file-based ZK.