Test Data Glossary Definition

Test data is a held-out dataset used to evaluate a trained model after model selection and tuning decisions are complete.

Test Data is a software-quality concept used in DevOps to move validation earlier, automate feedback, and reduce the risk of defects reaching production.

It should remain separate from training and validation data so final evaluation better reflects how the model may perform on unseen examples.

Quality engineers and developers use this concept to detect defects earlier, improve confidence in changes, and keep delivery speed from outrunning reliability.

Related concepts include DevOps, Continuous Testing, Test Automation and Quality Gate.