Google Books: A Metadata Train Wreck

Can we observe the way “happiness” replaced “felicity” in the seventeenth century, as Keith Thomas suggests? When did “the United States are” start to lose ground to “the United States is”? How did the use of propaganda rise and fall by decade over the course of the twentieth century? To answer those questions you need good metadata. And Google’s are a train wreck: a mish-mash wrapped in a muddle wrapped in a mess.