Latent Semantic Indexing (LSI) is a novel information retrieval method developed at Bellcore. By using statistical algorithms, LSI can retrieve relevant documents even when they do not share any words with your query. LSI uses these statistically derived "concepts" to improve searching performance by up to 30%. You can get more details about LSI and several applications.
The link to a knowledge of the future:
Latent Semantic Indexing Search