Community:Search/Search Results Order

From NSDLWiki

Ordering of Search Results

Search results are ranked according to a combination of factors including:

How often each query term appears in the document

Where "document" means a "hit" or result. This is a measure of how well the document matches the query.

How many documents in the entire set contain the term.

This is a measure of how well the term distinguishes among documents in the set.

"Normalization" for the size of the field.

A term appearing once in a short field is ranked higher than a term appearing once in a longer field.

Also, for multiple term queries:

How many query terms are in the document.

A document that contains both query terms scores higher than a document that contains only one term but contains it twice.

Query boosting factors.

Are query terms of equal weight, or do some get more weight than others?

Currently, NO boosting is done at indexing time: all documents are created equal, and fields and terms are created equal in the search index.