An atlas of human–computer interaction
The Periodic Table
of the Interactions
One hundred and eighteen ways people and computers make contact, from the command line to the prompt, laid out the way chemistry lays out matter, so the whole design space can be seen at once, gaps included.
Jade Flowers · Second edition, 2026
Arrow keys traverse the table · Enter opens an element
How to read it
Across →
What you hand the machine.
Each column asks one question. In row 3, Pick says which thing, Drag which way, Choose which one, Fill in what words.
Down ↓
What it has to keep track of.
Each row down, the machine holds more, so the same act gets heavier.
Empty on purpose. Until a machine remembers your work, there is nothing to copy, undo or save.
The AI era
In row 6 it guesses. In row 7 it acts.
The two series at the bottom of the table are what you do about it: check its guess, or watch, take back and end its errand.
Introduction
2026Nearly fifty-five years after the personal computer revolution, the actual atomic gestures of computing, the clicking, the scrolling, the dragging-and-dropping, have barely evolved.
The revolution hasn’t happened yet
Our ways of interacting with and within computational mediums look much as they did when Xerox PARC set them down. Alan Kay, whose work there instigated that revolution more than anyone else’s, put it plainly, and the line is now entering its third decade of being correct:
“The computer revolution hasn’t happened yet.”
We are still, by and large, shuffling windows to and fro, seeing what we get instead of what we might mean.
Not the interactions. The interlocutor.
But something has changed. In 2021 I was trying to show that the space of possible interactions extended well beyond PARC’s two-dimensional configuration, into territory I called “four-dimensional”: interactions with extra channels of information layered over the direct experience, where people could transcend the designed system and do things its designer made possible but never anticipated.
AI has since pushed us into that territory. The question is no longer whether we get there, but what we build when we arrive. So the second edition revises roughly a third of the table for interactions that didn’t exist five years ago: prompt composition, loading context, handoff zones, and undoing an agent. The essay that accompanies it has been rewritten from the ground up, because the argument has leveled up.
How to read a tile
Chemistry orders matter by atomic number and electron shell. This table orders interaction by what you hand the machine and what it has to keep track of, then marks every tile with properties a designer can actually reason about. Two are new this edition and sit on every tile’s face: authority, the disc, and initiative, the tick beside it.
- Authority· New
- Who is steering, you or the machine, and how tightly?
- Initiative· New
- Who opens the exchange: you, the machine, or either side?
- Dimensionality
- Does it live in text, on a surface, in a simulation, or somewhere stranger?
- Temporality
- Does it happen in an instant, or unfold over time?
- Discoverability
- Can you tell what it does by looking, or must you invest something first?
- Accessibility
- Is there an equivalent path for someone who can’t perform it as designed?
Arrange interactions along these axes and something remarkable happens: you start to see the gaps. The combinations no one has tried. The territory between what we have and what we could have. Mendeleev’s table let chemists see the design space of matter, including the elements that hadn’t been discovered yet. This one is meant to do the same for the design space of human–computer interaction.
What would the contemporary version of “dealing lightning with both hands” look like?
This table is my way of looking.
Jade Flowers, March 2026