In praise of facets

Follow-up of the previous post, and more on the ways to escape the tyranny of entities in search results. In the quick exchange with Aldo Gangemi in the comments of this post, facets were suggested. I won't argue further with Aldo about facets at BabelNet being types or topics, because he will win at the end, and such a technical argument would lead us astray, far from the main point I wouyld like to make today. You might be uneasy on what facets and particularly faceted search mean, but you have certainly used them many times when searching e-commerce sites, to filter hundreds of laptop models by price, brand, screen size, memory size etc. Libraries, enterprise portals, and many more use faceted search, example below is the search interface of Europeana for "impressionism", the results being filtered by two facets, media type "image" and providing country "Netherlands".

Faceted search is a very intuitive way to search items in a data base. Using faceted search, the user creates at will its own algorithm of filtering, selection and possibly ranking. If you compare with the usual general search engine results, two major advantages appear. The search is multidimensional, and the algorithm is transparent to the user. The system does not apply fancy, smart but opaque algorithms, based on guesses of what the user is looking for. It provides an interface where the user's natural intelligence can be put into action. In short, faceted search provides a good collaborative environment where artificial and human intelligence work together, the former at the service of the latter.

Given the above, one can wonder why general search engines such as Google do not propose faceted search facilities over their results, instead of an unidimensional list of ranked results. A technical answer coming to mind is that such engines do not search items in a collection of objects of which semantic descriptions are stored in a data base, but resources indexed by keywords. That used to be true, but the argument does not seem to hold anymore in the current state of affairs. The Knowledge Graph, however it's implemented, is a data base where things have declared semantic types and properties which could be used for faceted search. It would be a good way to see types and properties defined by schema.org vocabulary put explicitly into action as facets (Creative Work, Person, Place, Event, Business, Intangible ...).

I cannot imagine that Google and al. have never thought about this. There are certainly technical hurdles, but I can't imagine they could not be solved. So I would be curious to hear what they have to say, given that the added value to the search experience would be tremendous. Above all, it would give back to the user the power to define her own filtering on results, and reinstate the habit to do so, instead of the reductionnist Q&A dialogue which in the long run leads to pernicious intellectual laziness, unique thought, and jumping to conclusions without further checking. Our world is more and more complex, and offering simplified and unidimensional answers (presented as facts) to any question does not help to cope with complexity. Current events show us too many examples of oversimplifications and where they lead to.

I think of any of my queries to a search engine as a beam of light sent through the night of my ignorance, where possible answers are hiding as so many complex multi-faceted diamonds. I don't want any one of them, however brilliant and wonderful, make me blind to the point of missing all the rest. Every faceted answer should reflect back a new and unexpected part of the spectrum, without exhausting the question we should always keep alight.