Latent semantic analysis and indexing

Draft

Introduction

“Latent Semantic Indexing (LSI) is an indexing and retrieval method that uses a mathematical technique called Singular value decomposition (SVD) to identify patterns in the relationships between the terms and concepts contained in an unstructured collection of text. LSI is based on the principle that words that are used in the same contexts tend to have similar meanings. A key feature of LSI is its ability to extract the conceptual content of a body of text by establishing associations between those terms that occur in similar contexts.” (Deerwester et al, 1988 cited by Wikipedia

Links

• Latent semantic indexing (Wikipedia)

• Patterns in Unstructured Data, A Presentation to the Andrew W. Mellon Foundation by Clara Yu, John Cuadrado, Maciej Ceglowski, J. Scott Payne (undated). A good introduction to LSI and its use in search engines.