A varredura de parâmetros is a systematic method usada em aprendizado de máquina and other computational fields to explore the effects of different hyperparameters on the performance of a model. In essence, it involves running a series of experiments where a model is trained and evaluated multiple times, each time with a different combination of hyperparameter values. This technique is crucial for identifying the optimal settings that yield the best results for a given task.
In a parameter sweep, hyperparameters—those parameters that are set before the learning process begins, such as taxa de aprendizado, batch size, and number of layers—are varied across specified ranges or discrete values. The results from each configuration are then analyzed, typically using metrics such as accuracy, precision, recall, or F1 score, depending on the specific objectives of the model.
As varreduras de parâmetros podem ser categorizadas em dois tipos principais: busca em grade and busca aleatória. In a grid search, all possible combinations of hyperparameters are explicitly defined and evaluated, which can be computationally expensive, especially in models with many hyperparameters. In contrast, random search evaluates a random sample of combinations, which can often yield comparable results with less computational effort.
Embora as varreduras de parâmetros possam significativamente melhorar o desempenho do modelo, they can also be time-consuming and resource-intensive. As a result, researchers often use techniques such as Otimização bayesiana or hyperband to optimize the search process. These methods aim to intelligently explore the hyperparameter space, reducing the number of experiments needed while still achieving high performance.