Latent Semantic Indexing

Indexing and retrieval method that uses singular value decomposition to identify patterns in the relationships between the terms and concepts contained in an unstructured collection of text.


Based on the principle that words that are used in the same contexts tend to have similar meanings.

"Latent": semantic associations between words is present not explicitly but only latently

For example: two synonyms may never occur in the same passage but should nonetheless have highly associated representations.

Latent Semantic Indexing Used for:


  1. Learning correct word meanings
  2. Subject matter comprehension
  3. Information retrieval
  4. Sentiment analysis (social network analysis)

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