Precision

How it is used

Usually discussed together with recall, because improving one often lowers the other. Precision matters most when a false positive is costly, for example blocking a real customer's payment as fraud.

Example sentences

1. The spam filter has 98% precision, so almost nothing it blocks is real mail.

2. We raised the threshold to improve precision, but recall dropped.

Common collocations

• high precision
• precision and recall
• improve precision
• precision at k

Related terms

• recallOf all the cases that really were positive, the share that the model managed to find. High recall means few missed cases.
• F1 scoreA single number that combines precision and recall by taking their harmonic mean. It is high only when both precision and recall are high.
• accuracyThe share of a model's predictions that are correct, out of all its predictions. A model with 90% accuracy is right on nine of every ten examples.
• confusion matrixA table that shows, for each true class, how many examples the model assigned to each class, so you can see at a glance which classes it mixes up.

This word in other fields

The same English word can have a different meaning in another field:

• precision · Software Engineering
• precision · Data Science & Analytics

More terms: Evaluation and Metrics

• test set
• validation set
• benchmark
• cross-validation