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{{see also|Machine learning terms}} | {{see also|Machine learning terms}} | ||
==Introduction== | ==Introduction== | ||
Machine learning | [[Test loss]] is a [[metric]] that measures a [[model]]'s [[loss]] against the [[test data set]]. [[Machine learning]] [[algorithm]]s measure their model's ability to make accurate predictions on unseen [[data]]. The test loss provides an assessment of a model's generalization ability, or its capacity for making accurate predictions when presented with new information that was not seen during [[training]]. | ||
The test loss is calculated by comparing the model's predictions on test data with actual values for target variables. This difference, known as an | The test loss is calculated by comparing the model's predictions on [[test data]] with actual values for target variables ([[labels]]). This difference, known as an [[error]], serves to measure how accurately predictions made on the test data reflect actual outcomes. It serves to reflect how [[well-fitted]] the model's predictions were to the actual data. | ||
Calculating a test loss requires consideration of the particular problem being addressed and desired properties of the model. Common loss | We want to minimize the test loss. A large test loss vs. [[training loss]] or [[validation loss]] might indicate that we are [[overfitting]] the model and might need to use [[regularization]]. | ||
Calculating a test loss requires consideration of the particular problem being addressed and desired properties of the model. Common [[loss function]]s include [[mean squared error]], [[mean absolute error]], and [[categorical cross-entropy]]. | |||
==Mean Squared Error== | ==Mean Squared Error== | ||
Mean squared error (MSE) is a commonly used measure when attempting to predict an ongoing target variable. MSE is calculated as the average of squares between predicted values and actual values | [[Mean squared error]] (MSE) is a commonly used measure when attempting to predict an ongoing target variable. MSE is calculated as the average of squares between predicted values and actual values (labels). | ||
MSE is a smooth and differentiable function, making it suitable for optimization | MSE is a smooth and differentiable function, making it suitable for [[optimization algorithm]]s such as [[gradient descent]]. Furthermore, MSE has the advantageous property of being sensitive to large errors; this means a model with an increased MSE is likely to make major mistakes in some instances in its test set. | ||
==Mean Absolute Error== | ==Mean Absolute Error== |