What is the main objective of dimensionality reduction in data science?

The main objective of dimensionality reduction in data science is to simplify models and reduce overfitting. By reducing the number of features (or dimensions) in a dataset, you are effectively eliminating some of the noise and complexity that can lead to overfitting – a scenario where a model learns not only the underlying patterns but also the random fluctuations in the training data. When models are simpler, they generally generalize better to new, unseen data.

Dimensionality reduction techniques, such as Principal Component Analysis (PCA) or t-SNE, help identify and retain the most important features while discarding less informative ones. This not only aids in building models that are easier to interpret but also improves computational efficiency. In many cases, with fewer features, the model achieves similar or even better performance on validation and test datasets.

The other options do not align with the primary goals of dimensionality reduction. Increasing the data size or maintaining all features do not reflect the purpose of dimensionality reduction, as it specifically aims to streamline the data. While enhancing data visualization can be a beneficial side effect, the core objective revolves around improving model performance and reducing complexity, which connects most directly to the idea of simplifying models and mitigating overfitting.