AI engineering glossary · Evaluation metrics

What is ECE (expected calibration error)?

Expected calibration error (also called ECE): A single number summarising miscalibration: predictions are split into bins, and the gap between each bin's average confidence and accuracy is averaged, weighted by bin size: ECE = sum of (n_b / N) * |accuracy_b - confidence_b|. Lower is better, and 0 is perfect.

Level: advancedTopic: Evaluation metrics

Expected calibration error: an example

If a model is 90% confident on a bin holding half the data but only 80% accurate there, that bin contributes 0.5 * 0.10 = 0.05 to ECE.

Related terms

More Evaluation metrics terms

Where you learn it

Expected calibration error is part of the AI Engineering Program, which teaches it with notes, a hands-on lab and an exam. The first lesson is free.

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