— LSI Graph, an LSI keywords generator
Latent Semantic Indexing is based on the principle that words that are used in the same contexts tend to have similar meanings. It assumes that words that are close in meaning will occur in similar pieces of text. 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. In fact, it is called Latent Semantic Indexing because of its ability to correlate semantically related terms that are latent in a collection of text.
Text does not need to be in sentence form for LSI to be effective. It can work with lists, free-form notes, email, Web-based content, etc. As long as a collection of text contains multiple terms, LSI can be used to identify patterns in the relationships between the important terms and concepts contained in the text.