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Grammar-Based CAPTCHA
Date: April 19, 2007 11:19PM

I had mentioned this CAPTCHA in another thread, but unfortunately I didn't know what it was called, or where to find it again. I came across it yet again a few minutes ago so I figured I'd bring it up here. This CAPTCHA focuses on proper grammar and spelling:
What do you think about this one? As rsnake had pointed out in the topic about blindly inserting words into content (the one where "African American" was substituted for "Black" on a Baseball calendar) it's usually difficult for a program to understand the context of a word. True, Microsoft Word's spell checker and autocorrect can, in most instances, notice the incorrect use of a word that may be a homophone such as "there", "their", and "they're", but there's many times where it suggests things that aren't right, or very odd. With that in mind do you believe this CAPTCHA to be an effective measure against automated procedures, or do you see it as easily circumvented?

Awesome AnDrEw - That's The Sound Of Your Brain Crackin'

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Re: Grammar-Based CAPTCHA
Posted by: WhiteAcid
Date: April 20, 2007 01:54AM

This has a few issues. Firstly, surprisingly many people is actually terrible at grammar, besides that it also means the visitors have to be able to understand the language the CAPTCHA is in, though this might not be that much of a problem as the content on the site will most likely be in the language the CAPTCHA is in.

Secondly, if an OCR program can read the image then applying grammar rules is pretty trivial.

In short I don't think this raises the bar enough to be worth the time.

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-WhiteAcid - your friendly, very lazy, web developer

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Re: Grammar-Based CAPTCHA
Posted by: kuza55
Date: April 20, 2007 03:30AM

If a computer can decode the CAPTCHA, but not figure out which one is the correct one its not a big blow anyway - there are only two possibilities presented in the CAPTCHA, and therefore they still have a 50% chance of getting it right.

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Re: Grammar-Based CAPTCHA
Posted by: Kyran
Date: June 07, 2007 12:54AM

WhiteAcid Wrote:
> Firstly, surprisingly many
> people is actually terrible at grammar,


- Kyran

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