Vocabulary

Understand the term. Connect the concept.

A practical dictionary of 512 AI, machine learning, mathematics, and programming terms from HerbDev’s AI Vocabulary app. Start with a definition, explore an example, then follow the concepts behind it.

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F1 Score

Model Evaluation · Level 2 of 5

F1 Score

The harmonic mean of precision and recall.

It balances two rates while ignoring true negatives.

Example

A classifier with high precision but low recall receives a reduced combined score.

Listen to the definition and example

Audio transcript

F1 Score. The harmonic mean of precision and recall. It balances two rates while ignoring true negatives. For example: A classifier with high precision but low recall receives a reduced combined score.

Explore this concept

A useful analogy

A balance that is pulled down when either of its two sides is weak.

Why it matters

This helps you ask what a reported score counts and which errors it can hide.

Technical detail

F1 = 2PR / (P + R) = 2TP / (2TP + FP + FN), where defined. Multiclass macro and micro averaging differ.

Common misconception

F1 is not an arithmetic average and does not account for true negatives.

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Related concepts

Quick recall question

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Put the terminology into context: How AI works · Machine-native representations · All learning paths

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