Definition
Plain language
A slice of the model's internal number space — some of its directions, not all of them.
As stated in the literature
A linear subset of a representation space; projection-based edits act only within a chosen subspace, leaving information encoded in orthogonal directions untouched, which is why learning can route around a simulated ablation.
Also called: subspaces
Why it matters: It explains why removing one direction is not the same as removing a capability — the information can simply be re-encoded in a direction the edit never touched.
For example, an edit that removes one internal direction is like erasing a single line of an address while the rest of it stays perfectly readable.
Heard on the show
“And it's a subtraction inside one specific subspace, which means anything represented in the directions it doesn't touch comes through untouched.”Episode 244 — The Open-Weight Defense That Feeds Attackers Confident, Falsified Answers