AIExplainer
Machine Learning Intermediate 2 min read

What is negative sampling?

A technique used in machine learning to train models by selecting a subset of negative examples

Negative sampling is a method used to improve the efficiency of machine learning models, particularly in tasks such as natural language processing and recommender systems. It works by selecting a small set of negative examples from a large pool of possibilities, rather than using all of them. This helps to reduce the computational cost and improve the model's performance.

Imagine you're trying to learn what a cat is by looking at pictures of animals. Instead of showing you every single picture of an animal that is not a cat, negative sampling would show you just a few examples of dogs, birds, and fish, and ask you to distinguish them from cats. This helps you learn what a cat is not, which in turn helps you learn what a cat is.

For example, in a movie recommender system, negative sampling might be used to select a subset of movies that a user is unlikely to watch, in order to train the model to recommend movies that the user will enjoy.

Negative sampling is commonly used in tasks such as text classification, sentiment analysis, and recommender systems. It is particularly useful when there is a large imbalance between positive and negative examples, as it helps to reduce the impact of this imbalance on the model's performance.

One common misconception about negative sampling is that it is only used for binary classification tasks. However, it can also be used for multi-class classification and regression tasks.

Negative sampling has been used in machine learning for several decades, but it has become increasingly popular in recent years with the rise of deep learning and natural language processing.

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