I’ve been in love with the outliner since I first met OmniOutliner (later Workflowy, Dynalist, and now @RoamResearch).

Here’s why I think it’s so fundamentally important.

The outliner is the closest-to-sweetspot interface we have between a human brain and a computer brain. 👇

Humans are embodied spatial navigators. Even those of us who think we aren’t spatially gifted have the ability to instantly generate a mental map of everything in a room that we just walked into. We’re constantly measuring distances, tracking movement, triangulating.

Computers are disembodied rows of switches that grow in capability as they abstract and normalize increasingly complex patterns of rows of switches.

Computers need valid, consistent data. Their rock-solid reliability is tied completely to how inflexible they are.

Humans are flexible enough to take in any kind of data at any time, but they are inconsistent, unstructured, and the only workable systems they have for organizing are based on spatial, real-world paradigms like “files” and “folders.”

To illustrate: People who win memory contests don’t win them by building databases in their minds with rows and columns. They win by imagining a “Mind Palace” that they walk through and know where all the items are.

We know where things are by where we reliably find them.

This is why the vast majority will always be more comfortable with files and folders than with tagging, relational databases, other abstract computer organization paradigms, even if those interfaces are Better™.

Enter the outliner: The perfect blend between space and structure.

The outliner is both highly structured (rigidly so) and totally freeform, simultaneously. Its primary characteristic is its infinitely-nestable hierarchy.

On the human side, this hierarchy works a lot like files and folders where the “files” behave as “folders” themselves.

On the computer side, every block has one parent and unlimited children and grandchildren, forever.

Roam’s page and block reference behavior/interface has managed to not affect the compromise between human and computer at all. These features have managed to make Roam somehow better both for the human brain and the computer brain.

A yet-unexplored frontier in outliners is the sibling relationship and inheritance up, down, and laterally in the hierarchy. I think OmniOutliner made a pretty big mistake by adding rigid spreadsheet columns.

I’m very curious what @RoamResearch has planned for its Attributes.

To sum up: Files and folders are too human-y and miss out on most of the advantages of a computer. Tagging, databases, and all the varying representations of both are too computer-y and are unnatural and fatiguing for humans to grapple with.

Outliners strike the perfect balance.