What is 'Sparsity' in data?

What is 'Sparsity' in data?

Approach: Describe a dataset where most values are zero.

Sparsity occurs when a large percentage of the entries in a dataset or matrix are zero. It is common in text data (word counts) or recommendation systems (user-item ratings).

Follow-up: How does L1 regularization encourage sparsity?

Key concepts: high dimensionality, one-hot encoding, storage.