Telemetry glossary — the words, explained

Agreed tolerance

formerly: ε · bounded error · bound

In everyday terms: At the bakery, the scale label may be a few grams off either way, and the law allows for it.
What it means here: How much each reading may vary after it is stored. Whoever uses the data chooses it; the tool never exceeds it. Older pages called it ε (epsilon) or "bounded error".
Where it appears: TUBE CLAMP The tolerance is already in the standard

Smaller file, within tolerance

formerly: lossy compression

In everyday terms: A JPEG photo takes less space because it drops details the eye cannot see.
What it means here: Lossy compression: the file opens slightly different from the original, but never beyond the agreed tolerance, and that is checked reading by reading.
Where it appears: TUBE Certified surprise

Proof anyone can check

formerly: certificate · attestation

In everyday terms: The receipt with a barcode an inspector checks without calling the shop.
What it means here: What older pages called a certificate or attestation: the guarantee comes with what you need to redo the check, without trusting us.
Where it appears: TUBE CLAMP SIEVE Evidence platform

Compact summary

formerly: sketch

In everyday terms: The toll gate counter: it does not keep every car, it keeps the total per hour.
What it means here: What was called a sketch: a small structure that answers questions about a huge stream without keeping it all. TRUSS guarantees it cannot be gamed.
Where it appears: TRUSS

Question answered without opening the file

formerly: query on compressed data

In everyday terms: Finding a chapter through the book's index, without reading the whole book.
What it means here: Query on compressed data: the tool reads only the blocks that could hold the answer and returns a range guaranteed to contain the true answer.
Where it appears: CLAMP Market surveillance

File fingerprint

formerly: hash · seal

In everyday terms: A banknote's serial number: if anyone tampers with it, it no longer matches.
What it means here: The hash, or seal: a short code computed from the whole file. Change a single digit and the fingerprint changes.
Where it appears: GIRDER SHORE

Ledger

formerly: ledger

In everyday terms: The notary's book: each new line depends on the previous one, and nobody can tear out a page without a trace.
What it means here: A record in which every entry carries the previous entry's fingerprint and a signature. Tampering with the past breaks the chain.
Where it appears: GIRDER Evidence platform

Leave no result out

formerly: recall 1.0

In everyday terms: At school roll call, every student present must answer, not just most of them.
What it means here: What was called recall 1.0: the search guarantees that every item matching the query shows up. It has a cost, and the cost is stated.
Where it appears: SIEVE

Similarity search

formerly: vector search · retrieval

In everyday terms: Asking the shop assistant for "something like these shoes" instead of giving the exact code.
What it means here: Vector search: every item becomes a list of numbers, and "similar" becomes "close". SIEVE does this search without leaving any out.
Where it appears: SIEVE

How much it handles, how long it takes

formerly: throughput · latency

In everyday terms: The supermarket till: how many customers per hour and how long each waits.
What it means here: Throughput and latency. The pages state both, because a good number on one often costs the other.
Where it appears: SIEVE TRUSS

Same result on any machine

formerly: deterministic

In everyday terms: A recipe that bakes the same cake in any oven, down to the last decimal.
What it means here: Deterministic: the file comes out identical, byte for byte, on the server, the laptop and the browser. That is what makes sealing with a fingerprint possible.
Where it appears: TUBE GIRDER

Block of readings

formerly: GOP

In everyday terms: The chapters of a book: you can open one without reading the others.
What it means here: What was called a GOP: a stretch of readings stored together that can be read on its own. It is what lets questions be answered without opening the whole file.
Where it appears: TUBE CLAMP

The gap between predicted and measured

formerly: residual

In everyday terms: The forecast said 25 °C, it was 27 °C: the gap is 2.
What it means here: The residual. The compressor predicts the next reading and stores only the gap; when the gap grows too large, something has happened.
Where it appears: TUBE Certified surprise

Surprise

formerly: compressor surprise

In everyday terms: The noise that makes you look up: not the loudness, but what breaks the pattern.
What it means here: When a reading escapes what the compressor predicted, it spends more bits there. That "surprise" becomes an event detector, for free.
Where it appears: Certified surprise An undersea internet cable that became a seismograph The power grid reports its own blackouts

Confidence range with a guarantee

formerly: conformal

In everyday terms: Saying "I'll arrive between 6 and 6:30 pm" and being right 95 times out of 100, counted.
What it means here: What was called conformal: instead of a single number, a range with a guaranteed hit rate, checked on the data itself.
Where it appears: CLAMP Evidence platform

Proof of absence

formerly: certified absence

In everyday terms: The guard who does not just say "nobody came in": he shows the recording of every door.
What it means here: Proving that an event did NOT happen, touching only what is needed from the file. It is the hardest question to answer, and the one treaties and audits ask most.
Where it appears: CLAMP SIEVE

Fibre that becomes a sensor (DAS)

formerly: distributed acoustic sensing

In everyday terms: A phone line where every metre "feels" someone stepping nearby.
What it means here: DAS, distributed acoustic sensing: an ordinary optical fibre cable becomes thousands of vibration sensors, one every few metres.
Where it appears: An undersea internet cable that became a seismograph The band filter was already a proof