If you’ve got an Internet connection, chances are you’ve seen a Buzzfeed quiz. Or taken 20.

The “science” behind the viral news site’s ubiquitous quiz template, however, isn’t as easy to come by.

For instance, how could this happen?

Hannah Horvath  is a Marnie? She’s not the first Buzzfeed quiz-taker to get a head-scratching result — Shirley Manson, of Garbage fame, took the site’s “Which 90s Alt-Rock Grrrl Are You?” quiz and learned she was no Shirley Manson.

Aaron Bycoffe, a journalist and web developer who works for the Huffington Post, created a bookmarklet, dubbed BuzzCheat, that may help explain why. BuzzCheat sheds some insight into how Buzzfeed’s quiz results are calculated. It can help you figure out why you belong in California and not New York. Or whether you picked the wrong life philosophy.

Bycoffe explained the bookmarklet in a post on Wednesday, noting that his code “makes certain assumptions based on a small sample of quizzes that might not be true for all of them.” He also points out that more than one combination of answers can yield a particular result.

Summer Anne Burton, Buzzfeed’s managing editorial director, echoed that disclaimer on Twitter.

The formula — whatever it is — is working. Nieman Journalism Lab uncovered some of the thought-process behind Buzzfeed’s steady churn of quizzes. Last year, editors at the social news site discovered that a personality quiz called “Which ‘Grease’ Pink Lady Are You?” had been digitally shared more than any post in 2013. That metric led to more quizzes like “What City Should You Actually Live In,” which generated nearly 20 million views.

I tested BuzzCheat on that quiz and was curious about which responses could land me in Paris.  A desire to eat bread and drink wine, which makes sense because French women don’t get fat.  Answering #blessed for hash tag of choice could also yield Paris as a result, revealing at least one quirk in BuzzFeed’s calculations: a hashtag isn’t a hashtag in France. The term is mot-dièse.