"Google and DuckDuckGo appear to value quantity over quality. >From DuckDuckGo I frequently get responses of form: Including results for ... Search only for ... ? The first mutates your search terms to those in its approved vocabulary. The second condescends to search for your desired terms. Another major problem is they return a set that is a logical union, rather than logical intersection, of the specified set of elements."
This is a bit over my head, and maybe yours too, but this seems to be the closest thing I can find to what you're looking for. I think if you want better quality search results that, you're probably going to have to do so some work customizing your search methods with a search tool like Elasticlunar.js that provides a customizable browser search features: 3. Field-search, you could choose which field to index and which field to search. 4. Boolean Model, you could set which field to search and the boolean model for each query token, such as "OR", "AND". 5. Combined Boolean Model, TF/IDF Model and t It also supports off-line search so you can save the search results, review them, make changes to the search parameters, compare & contrast, refine and hopefully get better search results over time. Anyway, this is interesting to me, but not something I need. http://elasticlunr.com/ HTH
