As the group behind the project explains: There's an "intellectual judgment embedded" in the lists of books college students are required to read. The most frequently-assigned books at the nation's universities are essentially our canon: the body of literature that society's leaders are expected to be familiar with. So what does that canon look like?
For starters, the Explorer lets us filter by individual schools. I tallied the most frequently assigned books at all U.S. colleges and universities and compared them to the list at seven Ivy League schools — Harvard, Yale, Princeton, Cornell, Columbia, U. Penn and Brown (Dartmouth doesn't seem to appear in the Explorer's database — more on that below).
Across all schools, Strunk & White's classic writing guide "The Elements of Style" is the most common book, assigned in over 3,000 courses in the Explorer's database. Plato's "Republic" is the second-most popular, appearing close to 2,500 times. The 1,500-page "Campbell Biology" textbook/doorstop comes in at third place, perhaps a nod to the nation's pre-med students.
Appearing fourth on the list, Marx and Engels's "The Communist Manifesto" is sure to raise some eyebrows. Its popularity makes a certain amount of sense, given that it may be the most well-known critique of the capitalist system we all know and love. But that's not likely to comfort anyone who's convinced the nation's universities are breeding grounds for bearded Marxist extremism.
The Ivy League list is considerably different, however. Plato's "Republic" is the top book there, with Samuel Huntington's "Clash of Civilizations" coming in a close second. "The Elements of Style" makes an appearance, as do poli-sci classics "Leviathan" and "The Prince." Martin Luther King's "Letter from a Birmingham Jail" comes it at No. 8 in the Ivy Leagues.
Overall, the Ivy League list is heavily skewed toward political philosophy and thought -- the only book on the list that doesn't fall under this category is Strunk and White's "Elements of Style."
The Explorer lets you filter by subject area, too. Here's how the Ivies compare with everywhere else in English courses.
There's a little more agreement here, with five books in common across the two lists. The No. 1 work of fiction taught at American schools is Mary Wollstonecraft Shelley's "Frankenstein." At the Ivies, on the other hand, Chaucer's "Canterbury Tales" are No. 1 (raise your hand if you still bear psychological scars for having to memorize Middle English verse during your formative years).
Milton's "Paradise Lost" is universally assigned, as are Conrad's "Heart of Darkness" and Shakespeare's "Hamlet." But across all schools, works by American authors (T.S. Eliot's "Love Song of J. Alfred Prufrock," Charlotte Gilman's "The Yellow Wallpaper") are more commonly assigned than at the Ivies, where British authors are more prominent.
The Explorer also lets you filter only by colleges and universities in a given state. Here, for instance, is a map of the most-frequently assigned college course book in each state. The text is tiny, so click on the image to enlarge it if you need to.
"The Elements of Style" is the No. 1 college book in 13 states. "The Communist Manifesto" is also popular, showing up as No. 1 in six states. But there's a lot of variety otherwise. In Delaware, for instance, the top college book is a computer programming textbook. In Alabama, physics is king. Alaska appears to be a breeding ground for future petroleum engineers, while students in Nevada get a firm grounding in how numbers can be deceiving.
The folks who built the Open Syllabus Explorer are the first to admit that their data are incomplete and likely contain a fair number of errors. They've built their list by scraping publicly-available college websites, as well as submissions from individual professors. So if a college doesn't put course syllabi on public-facing pages (see the case of Dartmouth College, above), it's not going to show up in the list.
Still, with more than 1 million syllabi in the database, it's currently the best approximation we have for what students are actually reading in college -- and for the books that are informing the leaders of tomorrow.
CORRECTION: A previous version of this story misstated the name of Dartmouth College as "Dartmouth University." The author also wrote "it's" instead of "its" at one point, which several English professors scolded him for.