Vector Space Model The vector space model provides a way of comparing a multiterm query against a document. The output is a single score that represents how well the document matches the query. In order to do this, the model represents both the docum
Theory Behind Relevance Scoring Lucene (and thus Elasticsearch) uses the Boolean model to find matching documents, and a formula called the practical scoring function to calculate relevance. This formula borrows concepts from term frequency/inverse d
Field-length norm How long is the field? The shorter the field, the higher the weight. If a term appears in a short field, such as a title field, it is more likely that the content of that field is about the term than if the same term appears in a mu