The trick is to include a variety of results early. Sources often can be grouped into blocks which return mostly the same results. Better to reduce the quantity

The trick is to include a variety of results early. Sources often can be grouped into blocks which return mostly the same results. Better to reduce the quantity of returns from the top block in order to include on the front page a few from the second and third tier. Or maybe a text search equivalent to Yelp’s “re-search in this area” (after narrowing the map). Perhaps to be able to select some results and hit a “more like this” button.