Definition
Plain language
A compact summary that sits at the center of a group of similar items.
As stated in the literature
The representative point (often a mean vector) of a cluster, maintained and updated incrementally in stream-clustering systems to assign new items to the nearest group without re-clustering everything.
Also called: cluster centroid, centroids
Why it matters: It matters because it lets a system sort streaming data into groups on the fly without re-examining everything it has seen before.
For example, a system grouping news articles might represent the whole 'sports' cluster by a single central point and file each new article under whichever center it sits closest to.
Heard on the show
“… slot and drop the middle one — because otherwise the middle child would collide with the parent's centroid and you'd lose uniqueness. …”Episode 042 — An Agentic Scientific Computing System That Actually Remembers What It Learns