Hacker News Reader

Comment by brlewis | Hacker News Reader

This was just answered on Quora: http://www.quora.com/How-does-Facebook-predict-my-photo-albu...

Henry F. Bridge, Product Manager, Facebook

Photo albums on Facebook have long had a text input field for location, but until recently, there was no way to put in structured data in this field (like a Facebook page). We added that ability earlier this year, and the "add a location" feature just performs a search on whatever text the album owner put in originally (ranked by place popularity etc) and suggests the first result as the location of the album.

View on HN

I uploaded pictures from a class trip on Facebook back in 2009 and had no captions or names that suggested that the pictures were taken in California. My camera at the time was not capable of GPS. Facebook still managed to get the location right.

Scary stuff.

Like I said on Quora, we use the location field that you put into the album when you uploaded it. The album location isn't displayed in the caption for individual photos and isn't displayed that prominently on the album page, so you're probably just not seeing that you set it when it was uploaded in 2009.

I never entered anything into the location field (I would have remembered doing it), yet it got the exact city and state where I took the photos.

You specifically remember leaving a form field blank on a web page three years ago?

I would have remembered when the message to tag the location of my photos came up.

It didn't work like that. It was a plain blank text field among a couple other blank text fields. No search was brought up upon data entry. Very innocuous; Perhaps that why you don't remember it.

Believe me, I would have remembered doing it. I wouldn't have cared about a location tagging message if I had entered the location manually. Not to mention I couldn't even remember the names of some of the cities where the photos were taken until Facebook suggested them to me.

Very sophisticated. Almost like magic :)

Reply on news.ycombinator.com