We love it, of course, when the DDC gets a shout-out—particularly when reference to it reflects how widely known it is and even more so when someone recognizes its usefulness. Such is the case in Nate Silver’s blog posting, "What the Fox Knows." The shout-out to Dewey comes after Silver notes that the way he organizes the collection of ca. 500 books in his office—by color!—isn’t scalable:
But what if instead of having 500 books, I had 50,000, or 50 million? At that point, I’d need a more rigorous approach toward classifying the books — alphabetical order, or the Dewey decimal system, or whatever else. Otherwise, I might spend hours trying to find my copy of "What It Takes."
The DDC is right up there with alphabetic order, which is pretty heady stuff. But come to think about it—and we’re sure Silver would have said so if he had thought about it—Dewey is better than alphabetic order in a large number of contexts. While alphabetic order is great for finding the single volume whose title you know (and remember accurately), it doesn’t help you find related works; their titles are likely to be scattered across the alphabet. Author/title alphabetic order is only a little better. But look up the title in a catalog, find its Dewey number, and that number will find related works. Or, if you don’t know any title on the subject of interest, search in the catalog for title keywords or subject headings, find a relevant title, then use its Dewey number to find related works. Or look up the subject in the Relative Index (and verify its relevance in the schedules), and you are way ahead of what alphabetic order can do for you. In a collection of 50 million, there are likely to be works in more than one language, and you may wish to share them with people who have different mother tongues; Dewey numbers are good at crossing linguistic boundaries, especially since the Relative Index and schedules have been translated into many languages.
For the record, the Dewey number for What it takes: the way to the White House is 324.9730927 Elections -- United States -- 1981–1989. Searching on that number in WorldCat retrieves 249 records. Limiting the search to those on the 1988 election, which is the focus of What it takes, retrieves 102 records, including, for example, Whose broad stripes and bright stars?: the trivial pursuit of the presidency, 1988, which might not be so very far away in an alphabetically-organized collection (depending on its size), and Almanac of 1988 presidential politics : a political junkie's handbook of the 1988 campaign year--the candidates, campaigns, polls, schedules, dollars, debates, advertising, and chronology--the best, the worst, the laughs, the gaffes, which would be far distant. The number 324.9730927 is built using the add instructions at 324.91–324.99 Geographic treatment of elections, which tell us to "add to base number 324.9 notation 1–9 from Table 2 . . .; then to the result add historical period numbers from appropriate subdivisions of 930–990 . . . . In all cases use one 0 except 00 for North America and South America." Therefore to 324.9, we add notation T2—73 United States, plus 0 (the exception for North and South America does not apply to individual countries within North and South America), plus notation 927 from 973.927 Administration of Ronald Reagan, 1981–1989.