NEW YORK — – In baseball, trend-spotting tends to be based on statistical analysis. In fashion, it’s driven by runway shows. And when it comes to social networks, the ascendant paradigm for forecasting the future seems to center on first-person anecdotes and unsupported hearsay from random teenagers.

Earlier this year it was Josh Miller’s unnamed 15-year-old sister who drove the media conversation around the alleged decline of Facebook and the rise of Snapchat, Instagram and Tumblr. This week it’s a post on the social media blog Mashable by a 13-year-old HelloGiggles correspondent named Ruby Karp. Her post, headlined “I’m 13 and None of My Friends Use Facebook,” has garnered some 36,000 Facebook shares since it was published Sunday. It has, predictably, launched a fresh armada of blog posts heralding the imminent fall of the great social network.

Media hype

“Is this the beginning of the end for Facebook?” one asks. “Is Facebook hurtling toward irrelevance, or is it already there?” wonders MSN. Mashable’s own Todd Wasserman was moved by Karp’s post to speculate about whether Facebook is the next Yahoo. The Huffington Post this week is hosting a live video segment centered on the question, “Without Teens, Does Facebook Have a Future?”

That’s an interesting hypothetical. But – call me old-fashioned – I’d prefer to draw data from a slightly wider sample than Ruby Karp and Josh Miller’s sister before drawing firm conclusions about the death of Facebook among teens. To be clear, I’m not saying that posts like Miller’s and Karp’s are without merit. When analyzing the prospects of billion-dollar companies whose fortunes rely in significant part on their cachet among young people, it’s great to hear from some actual teens now and then among all the middle-aged talking heads. But the sweeping generalizations some media outlets were quick to make on the basis of Karp’s blog post left me wondering: Did they actually read it?

Too many parents?

“Although I do have a Facebook, none of my other friends do,” Karp writes. “My friends just thought it was a waste of time.” But Karp says she soon discovered that “Facebook is useless without friends,” adding, “My only friend is, like, my grandma.”

OK, got it. Facebook is dead to Karp because none of her friends use it. But wait – that’s not the only problem with the social network. Two paragraphs later, Karp adds that Facebook is also dead because all of her parents and her parents’ friends are on it. And why is that a problem? Because, Karp says, “my friends post photos that get me in trouble with those parents.”

Ah yes – the old “parents are ruining Facebook” problem. But wait a minute: If none of Karp’s friends are on Facebook, how do they keep managing to post such troublesome photos on the site? The contradiction is compounded when Karp laments that “Facebook is also a big source of bullying in middle school.” Kids might “comment something mean on a photo of you,” she adds, “or message you mean things. This isn’t Facebook’s fault, but again, it does happen there.” How middle school bullying happens on Facebook if no middle schoolers are actually using it, Karp’s post does not explain.

Survey: Teens use Facebook

Yogi Berra once said of a St. Louis restaurant, “Nobody goes there anymore. It’s too crowded.” Karp’s critique of Facebook seems to amount to, “No teens go there anymore. It’s too crowded with other teens.”

When I asked Karp via email about the apparent contradiction, she told me the kids getting in trouble on the site are mostly older kids, while those in her age group don’t use it at all. I’m not convinced – I suspect Karp has a lot more friends on Facebook than she realizes, given a recent Pew study that found it remains by far the most popular social network among teens, even as others are gaining ground.

As Slate’s Amanda Hess put it, “Teenagers Hate Facebook, but They’re Not Logging Off.” That’s consistent with Facebook CEO Mark Zuckerberg’s recent assertion that the company’s internal data show the number of teens on Facebook holding steady over the past year and a half.

Facebook could go a long way toward defusing the “teens are quitting Facebook” narrative by releasing actual data to back up Zuckerberg’s claims, but it refuses to do so. The company, then, must take part of the blame for the media’s overreliance on cherry-picked anecdotes. Still, I’ll take a Pew survey over a first-person Mashable post any day. And besides, my 13-year-old nephew does use Facebook, and so do a bunch of his friends. But that doesn’t make for a catchy headline.

My goal here is not to bash Karp. Indeed, in our brief email interview, the 13-year-old was careful to add a crucial disclaimer: “My experience is limited to where I live,” she told me, “and the people I go to school with.” Funny how the professional tech bloggers who ran with her story seemed to overlook that point.