Cross-validation

How it is used

The most common form is k-fold cross-validation, for example 5-fold or 10-fold. You run cross-validation to get a more reliable estimate of performance and to compare models. Often shortened to CV in code and notebooks.

Example sentences

1. We used 5-fold cross-validation, and the scores were stable across folds.

2. With time series you can't use ordinary cross-validation, because the model would be trained on the future.

Common collocations

• k-fold cross-validation
• cross-validation score
• run cross-validation
• time-series cross-validation

Related terms

• overfittingA problem in which a model learns the training data too closely, including its noise, so it performs well on that data but poorly on new data.
• test setA part of the data that is held back and never used in training, so that it can show at the end how well a model works on data it has not seen.
• training dataThe examples, with known inputs and usually known answers, that a model learns from; they are kept separate from the data used to test the model.
• modelA mathematical representation of a real process, built from data, that is used to explain relationships or to make predictions about new cases.

This word in other fields

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

• cross-validation · Software Engineering
• cross-validation · Artificial Intelligence & Machine Learning

More terms: Modelling and Machine Learning

• feature
• regression
• classification
• accuracy
• precision
• recall
• baseline
• feature engineering
• target variable
• clustering