---
title: "Hat mathematical notation"
description: "Hat is a recurring research-paper notation family. Marks an estimate, prediction, or transformed version of the undecorated quantity."
canonical_url: "https://fanout.sh/labs/math-decoder/symbol/hat"
md_url: "https://fanout.sh/labs/math-decoder/symbol/hat.md"
last_updated: "2026-08-09"
access: "public"
---

# Hat mathematical notation

Hat is a recurring research-paper notation family. Marks an estimate, prediction, or transformed version of the undecorated quantity.

## Public overview

Hat: Marks an estimate, prediction, or transformed version of the undecorated quantity. Example: The model produces an estimated target y.

---
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