Entry 44 of 44
Signal
signum — mark, token, seal, indication
Latin
From Latin signum: a mark, a token, a seal, a sign by which something is known. In information theory (Shannon): the meaningful component of a transmission, defined against noise. Root concept: a mark that points. A signal is never self-sufficient. It is a sign of something.
Established meaning
In ordinary use: a sign meant to be read. In engineering: the component treated as information. The question 'signal of what, for whom, according to whose detector?' is built into the word. A signum has an author and a reader.
AI industry deployment
'Signal-to-noise ratio' as a boast. The signal is whatever the company's detector is built to find: a class of bugs, a class of harms, a class of user intents. Everything else is eligible for discard. The mark is treated as identical with the company's category.
Semantic gap
Whose mark
Signum is a pointing. Industry usage collapses the sign into the detector: signal is what we already know how to count. The question of who left the mark — whose voice is in the weights, whose opening is in the trust model — has been removed. Isolation of 'signal' becomes a way of not reading.