The research is using prices to determine the "best" paintings for an artist, but that means that their data for art is basically determined by the not-exactly-

The research is using prices to determine the "best" paintings for an artist, but that means that their data for art is basically determined by the not-exactly-quality-based forces involved in pricing art. "Van Gogh painted this one at the same time as X that sold for $$$$Y" is an effective selling point to certain segments of that market.