Flow/Architecture/Search/Relevance

ElasticSearch has a default implementation to calculate "relevance" of a "item" compared to your search terms. The way that works is described in detail on their website. This is used for sorting: by default, the search results are ordered by how relevant they appear to be for your search terms.

For Flow, there's support for multiple ways of sorting the data:


 * per relevance (the dafault ES relevance)
 * per topic creation date (ascending & descending)
 * per topic last change date (ascending & descending)

Apart from just using the relevance for sorting, we could also use it for other purposes. That relevance is just a floating point number, e.g.: 0.076713204. I don't think it makes much sense to display that number to users.

If we want to somehow display some other form of "relevance", we could calculate differen