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AI Native Terms

What Is Validation Data?

Written byre:cinq StaffUpdated 16 Sept 2026

Validation data is a sample of data used during an AI model's development to fine-tune its settings and check its performance before final testing. When building an AI model, it can easily "memorize" the specific examples it was trained on. This results in a model that performs poorly when it encounters new, real-world information it has not seen before, a problem known as "overfitting."

Continue readingHow it helps

How it helps#

By using validation data as a series of "practice tests" during development, developers can adjust the model to ensure it learns general patterns, not just memorized answers. This creates a more reliable and accurate AI that performs better on unfamiliar data, leading to better business outcomes.

How it works#

When building an AI model, the total available data is typically split into three sets. The largest set, the "training data," is used to teach the model the initial patterns and relationships.

During this training process, the model is periodically evaluated against the validation data, which it has not been trained on. Based on its performance on this validation set, developers can adjust the model's internal configuration to improve its ability to make accurate predictions on new data. This iterative tuning ensures the final model is as effective as possible before it is finalized.

How it is different#

Validation data is used to tune a model's settings during its development. It is different from training data, which is the primary dataset used to teach the model its core patterns. It is also different from test data, which is a completely separate set of data used only once at the very end of the process to provide a final, unbiased evaluation of the fully-trained model's real-world performance.

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Related terms

  • Training data

    What Is Training Data?

    Training data is the collection of examples, such as text, images, or sales figures, used to teach an AI system how to make predictions or decisions.

  • Overfitting

    What Is Overfitting?

    Overfitting occurs when an AI model learns its training data so perfectly that it fails to make accurate predictions on new, real-world data.

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