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Why reCAPTCHA is Good for Humanity

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Last week we talked about KittenAuth, a novel CAPTCHA system used to differentiate between humans and spambots -- by using pictures of kittens. Today let's take a look at reCAPTCHA, the system in use by this very blog. What does it do, and why is it good for humanity?

What's a CAPTCHA?

First let's review the term CAPTCHA. It's a loose acronym for "Completely Automated Public Turing test to tell Computers and Humans Apart." The idea is to force humans to do a (relatively) simple task like read a few words presented in an image, then type them into the form -- but this trick only works if the task is hard for computers (ahem, spambots) to do.

CAPTCHA systems are used on forms all over the web in order to cut down on spam form submissions. If you've ever run a blog, you'll know that legions of spambots are crawling the web, submitting every form they find -- so having a CAPTCHA on the form drastically reduces form spam. However, in most CAPTCHA systems the text you type in is meaningless, purposely scrambled text. reCAPTCHA is different.

What's Different About reCAPTCHA?

reCAPTCHA was born when Luis von Ahn, an assistant professor at Carnegie Mellon, realized that millions of people were spending time typing meaningless words into forms. Why not turn this word-decipherment into useful work that helped with some common goal? What if there was a set of words (as images) that needed to be viewed and deciphered by humans? It turns out that book scanning projects (including the Internet Archive) have just this problem: when scanning a print book into a computer -- particularly an old book in poor condition -- some words can't be deciphered automatically by Optical Character Recognition (OCR) software, and need a human to figure them out. In order to get a good text-only copy of a scanned book, lots of human attention is needed.

So reCAPTCHA is conceptually simple: take the words the OCR software can't read and put them in front of human users. If multiple users decipher the same hard-to-read word using the same text, reCAPTCHA can safely assume that it has been properly deciphered, and feed that word back into the book scanning project, slotting it into its associated book. Thus, text that is by definition difficult or impossible for a computer to accurately scan has been deciphered by humans -- and the humans doing the work generally don't even know it!

Yeah, But...

There's one technical catch -- what's to stop people from typing in random gibberish as "decipherment" of the words? Given that reCAPTCHA by definition doesn't know the correct decipherment of its subject words, how can it judge whether you've gotten it right? To solve this problem, reCAPTCHA presents two words together: one unknown and one known (the latter meaning a word for which reCAPTCHA already has a good decipherment). You have to get the known word correct, and the unknown word is (as described above) compared with other users' decipherments to eventually determine whether it's correct. There's also an audio variant for users with visual impairment, in which they listen to spoken language and convert it to written text.

So next time you fill out a reCAPTCHA form when commenting on a Mental Floss blog post, remember: you're helping to digitize books!

Further reading: Carnegie Mellon press release, Wikipedia page, reCAPTCHA project site.

Shhh...super secret special for blog readers.

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Google Maps Is Getting a Makeover With More Icons and Colors
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Prepare to get used to some big changes to your Google Maps app. The tech giant announced in a blog post that it’s changing the tool’s design to better highlight information that’s relevant to your journey.

The first update can be seen when switching between modes of transportation. If you’re driving from your home to work, for example, Maps will show you gas stations along your route, but switch to public transit and train stations will pop up instead.

The app’s color scheme has also been given a makeover. All points of interest (POI) that appear on the map are now color-coded. Looking for the nearest restaurant? Food and drink POI are orange. Need some retail therapy? Shopping icons are blue. Hospitals (pink), churches (gray), outdoor spaces (green), and more are included in the new system.

Within the larger categories, Google has introduced dozens of specialized icons to indicate subcategories. Banks are marked with a dollar sign, cafes with a coffee cup, etc.

“The world is an ever-evolving place,” Google Maps product manager Liz Hunt wrote in the blog post. “Now, we’re updating Google Maps with a new look that better reflects your world, right now.”

This overhaul is the latest way Google Maps is evolving to make life more convenient for its users. In the past year, the app has rolled out features that allow you to locate your parked car and to check how crowded attractions are at certain times. The new design changes will start appearing over the next few weeks.

Phones with maps app open.
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Color key for Google Maps.
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Icons for Google Maps.
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Facebook Just Made It Easier to Tell the Difference Between Fake News and Real Reporting
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On Facebook, fake news stories "reporting" international conflicts over Toblerones can appear alongside fact-checked journalism from trustworthy outlets. This leads to some bogus stories racking up thousands of shares while real news stories are deemed "fake" by those who disagree with them. With its latest news feature, Facebook aims to make the distinction between factual and fictional posts clearer.

As The Verge reports, articles shared on Facebook will now display a "trust indicator" icon. Clicking on it reveals information about the publisher of the piece, including their ethics statement, corrections policy, fact-checking process, ownership structures, and masthead. By providing that context, Facebook hopes that more users will make better decisions about which news outlets to trust and which to disregard.

The social media network is launching the feature with a handful of publishers and plans to open it up to more down the road. But unless it becomes mandatory for all media pages, it won't be the end of Facebook's fake news problem: Phony sites and real publishers that leave this information blank will still look the same in the eyes of some readers. Additionally, the feature only works when people go out of their way to check it, so it requires users to be skeptical in the first place.

If you want to avoid the fake news in your feed, looking for trust indicators is a good place to start. To further sharpen your BS-detecting skills, try adopting the CRAAP system: The American Library Association has been using it to spot sketchy sources since before the Facebook era.

[h/t The Verge]

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