Anyone who's read Franco Moretti's Graphs, Maps, Trees with care is likely to wonder about the periodizations of the novels in the first section, "Graphs." As Allen Beye Riddell puts it in a blog post from over two years ago
Moretti examines the history of arrival and disappearance of "novelistic genres" in Britain between 1740 and 1900. Examples of these genres include historical, gothic, and epistolary novels, as well as less familiar categories, such as silver fork novels and Newgate novels. Over the 160 year period, Moretti identifies 44 genres. And he detects a unexpected pattern: genres seem to arrive and depart in clusters.
Riddell is interested in verifying Moretti's periodization. He finds that it's not a straight forward process – and who's surprised about that?
I'm not going to attempt to summarize what Riddell's done; you'll have to read the post for yourself. He ends up checking the periodization for two genres, silver-fork novels and gothic novels, by identifying the intervals in which 95% of the novels appeared. He found that Moretti's periodization matched that fairly closely. He also notes that checking all 44 genres would be difficult because the relevant bibliographic resources aren't always adequate. He also notes in passing that "none of the genres are so mysterious that an interested student with some knowledge of British history and a handful of exemplars could not evaluate the case for the inclusion of a novel in a particular category."
Needless to say, this sort of work is essential if the project of "distant" reading is to go forward. It's brutal unglamorous work, but necessary.