[[not-quite-not]] === Not Quite Not A search on the Internet for ``Apple'' is likely to return results about the company, the fruit, ((("relevance", "controlling", "must_not clause in bool query")))((("bool query", "must_not clause")))and various recipes. We could try to narrow it down to just the company by excluding words like `pie`, `tart`, `crumble`, and `tree`, using a `must_not` clause in a `bool` query: [source,json] ------------------------------- GET /_search { "query": { "bool": { "must": { "match": { "text": "apple" } }, "must_not": { "match": { "text": "pie tart fruit crumble tree" } } } } } ------------------------------- But who is to say that we wouldn't miss a very relevant document about Apple the company by excluding `tree` or `crumble`? Sometimes, `must_not` can be too strict. [[boosting-query]] ==== boosting Query The http://bit.ly/1IO281f[`boosting` query] solves((("boosting query")))((("relevance", "controlling", "boosting query"))) this problem. It allows us to still include results that appear to be about the fruit or the pastries, but to downgrade them--to rank them lower than they would otherwise be: [source,json] ------------------------------- GET /_search { "query": { "boosting": { "positive": { "match": { "text": "apple" } }, "negative": { "match": { "text": "pie tart fruit crumble tree" } }, "negative_boost": 0.5 } } } ------------------------------- It accepts a `positive` query and a `negative` query.((("positive query and negative query (in boosting query)"))) Only documents that match the `positive` query will be included in the results list, but documents that also match the `negative` query will be downgraded by multiplying the original `_score` of((("negative_boost"))) the document with the `negative_boost`. For this to work, the `negative_boost` must be less than `1.0`. In this example, any documents that contain any of the negative terms will have their `_score` cut in half.