# Classifier
**Domain:** Machine learning / Decision systems
**Doc Type:** Developed Wiki Node
**Maturity:** Developed
**Collection:** [[collections/Gamification|Gamification Collection]]
## Definition
A **classifier** is a system that assigns an observation to one or more categories using rules, statistical models, or learned representations.
## Significance
In eligibility and security systems, classification becomes consequential when a category controls access, sanction, scrutiny, or future options.
## Sources
- [[articles/gamification/Lex Sportiva and Winning Without Bloodshed|Lex Sportiva and Winning Without Bloodshed]]
- [Primary or institutional source](https://developers.google.com/machine-learning/crash-course/classification)
## Routes
[[wiki/Cost Matrix|Cost Matrix]] · [[wiki/False Positive|False Positive]] · [[wiki/Eligibility Regime|Eligibility Regime]] · [[articles/gamification/Lex Sportiva and Winning Without Bloodshed|Lex Sportiva and Winning Without Bloodshed]]