Named Entity Recognition (NER) is a subtask of Natural Language Processing (NLP) that involves identifying and classifying key entities in text into predefined categories such as names, organizations, locations.

The process typically employs algorithms like Conditional Random Fields (CRFs) or deep learning models such as Bi-directional LSTM (Long Short-Term Memory) networks.

Mathematically, NER can be framed as a sequence labeling problem where the goal is to assign a label to each token in a sentence. The model learns from annotated datasets, optimizing parameters to maximize the likelihood using techniques like backpropagation.

NER has significant implications in information extraction, search engines, and automated customer support systems.

Important

  • NER transforms unstructured text into structured data for analysis.
  • The choice of model significantly impacts the accuracy of entity recognition.

Example

An example of NER is identifying “Apple Inc.” as an organization in the sentence: “Apple Inc. released a new product.”

Follow up questions

  • Text classification in NLP
  • Information extraction techniques