Is that because they are using AND instead of OR? I know that both Solr and Elasticsearch will return any document with at least one term if you use OR (the def

Is that because they are using AND instead of OR? I know that both Solr and Elasticsearch will return any document with at least one term if you use OR (the default). You can also use minimum_should_match in ES (don't know Solr equivalent) to control what percentage of terms should match. If the search engine's only difference is the use of OR or minimum_should_match, that isn't a compelling product because it is not significantly better than existing enterprise search products. In order for your competitor's customers to switch, your product needs to be significantly better. You also need to add search highlights to the results. There are two components to relevance: actual and perceived. In the product's current form, I have no idea if a result is relevant unless I click the document and read it. In other words, I am unable to perceive a search result's relevance. The highlight helps with that.