Terms related to neural networks · 3.4.1
activation function
a function applied to the weighted sum of all the inputs reaching a neuron
What this term settles
A governance lead borrows this meaning whenever activation function appears in a risk assessment or an assurance argument. The borrowing is safe only if the artefact behind it matches the description.
Who it binds
The entry has no shall in it. Its force comes from use: once activation function appears in a procedure or a supplier term, this is the meaning the reader is entitled to rely on.
What to do in your practice
Use the entry as a test in the next review. Ask the owner to point at the artefact that shows activation function in this sense, then record the answer with a date.
Evidence an auditor or regulator asks for
- A controlled vocabulary entry for activation function with the citation 3.4.1, an owner and a review date.An auditor can check that the term is controlled rather than assumed.
- A model architecture note that names the network form and the layers used.Shows activation function in use in the artefact the firm relies on, not only in a glossary.
- A test record that shows the behaviour the architecture was chosen for.The architecture note uses the network name as a marketing label with no layer or training detail behind it.
Common gaps this page catches
- activation function is used in the network architecture note without a written definition, so two teams can mean different things.
- A local synonym has grown up beside the entry and the two are now used interchangeably.
What to prepare before the amendment lands
Take the next policy revision and replace the loose use of activation function with the entry and its citation. Record the change in the vocabulary change log.
How to test it here
Take one live artefact rather than a template, find the sentence or field where activation function is used, and put this page beside it. Record the answer, the artefact and the date, because that record is the evidence and a glossary entry on its own is only an intention.
What this page does not claim
The page does not reproduce the standard, certify the firm or predict the wording the amendment will use; it states activation function at the claim level "definition" and stops where the public record stops.
Common questions
- What does activation function mean in ISO 22989?
- a function applied to the weighted sum of all the inputs reaching a neuron
- What evidence should we keep for 3.4.1?
- A controlled vocabulary entry for activation function with the citation 3.4.1, an owner and a review date. A model architecture note that names the network form and the layers used.
- Is activation function a requirement?
- No: activation function is a definition or clause of a terminology standard, and it becomes binding only when a firm writes it into a policy, a contract or a procedure, or when another standard incorporates it.
Related units
Source. ISO/IEC 22989:2022, Clause 3.4.1, Terms and definitions. Open the ISO public entry. Retrieved 21 October 2026.
https://www.iso.org/obp/ui/en/#iso:std:iso-iec:22989:ed-1:v1:en
ISO catalogue record 88145, the amendment status, stage and dates. Catalogue record 74296, the base standard.
Claim level: definition. The definition is in the public preview. This page states it in our own words and does not reproduce the text.
Last updated: 2026-10-21 · Markdown version · Check your vocabulary