test set

A subset of the dataset reserved for testing a trained model. Traditionally, you divide examples in the dataset into the following three distinct subsets: - a training set - a validation set - a test set Each example in a dataset should belong to only one of the preceding subsets. For instance, a single example shouldn't belong to both the training set and the test set. The training set and validation set are both closely tied to training a model. Because the test set is only indirectly associated with training, test loss is a less biased, higher quality metric than training loss or validation loss. See Datasets: Dividing the original dataset in Machine Learning Crash Course for more information.

Practitioners refer to test set when building, training, or evaluating machine learning systems. It appears in research papers, product documentation, and technical discussions about AI capabilities and limitations.