Comments on: CAPTCHA vs Human Logic

By: Amir Hossain

Amir Hossain — Tue, 25 Mar 2008 13:57:30 +0000

Hi!!! Hope you are doing well. We the leading Data processing company in Bangladesh. Presently we are processing 300000+ captcha per day by our 55 operators. We have a well set up and We can give the law rate for the captcha solving.

Our rate $2 per 1000 captcha.

We just wanna make the relationship for long terms. can we go forward? Thank you, (For inquiry amir4@yours.com or
khoknaa@yahoo.com)

Best Regards
Amir Hossain Dewan
Data Home Ltd.
amir4@yours.com
khoknaa@yahoo.com

By: TylerCruz.com: An Internet Entrepreneur’s Journey » MillionDollarWebTV.com Review

Fri, 21 Sep 2007 04:19:59 +0000

[...] just a personal preference/suggestion, but it’d be nice if they changed that to use a “Human Logic” question such as “What is the opposite of day?” or “What day comes after [...]

By: Nick Williams

Nick Williams — Mon, 16 Apr 2007 04:32:28 +0000

The problem(s) with this is that the tests have to be come up with manually. Thus the CA part of CAPTCHA [completely automated] does not stand. There are a finite set of questions that can be asked, and bots can still come up with the answer to something as simple as arithmetic or basic trivia. You also have the gray line that’s drawn between basic logic and advanced logic, the latter of which introduces regional conflict.

As the commenter above me suggests, and I agree, it’s all about circumstances. Websites like Blogger.com and Digg are best off with the more robust ubiquitous visual/audio letter/number CAPTCHA because it is most resistant to attack. However, spam bots in general are playing the numbers game… differentiating your blog/form from others simply by renaming a form field will prevent a lot of spam. That works in a situation (which I believe most common) where the form isn’t necessarily a target on its own, instead it’s a target because it’s a known vulnerable form (such as a Wordpress blog).

By: Matt

Matt — Sat, 14 Apr 2007 09:42:34 +0000

What some of you are missing/forgetting/… is that CAPTCHA’s are inaccessible to blind users.

Even some fully sighted people have issues with CAPTCHA’s.

I agree that perhaps “What sound does a cow make?” might not be the best logic question, but it’s more accessible than image CAPTCHA’s.

Is there a perfect solution? No. Will there ever be? No.

It’s all about what’s going to work best for your circumstances, whether that be an image CAPTCHA, a logic CAPTCHA or some other form of spambot detection.

By: TylerCruz.com - John Chow style Review Me for Linkback. | BlogBait.net

TylerCruz.com - John Chow style Review Me for Linkback. | BlogBait.net — Thu, 05 Apr 2007 22:19:21 +0000

[...] a few articles about Internet related and blog related topics. One great article I read was Captcha vs. Human Logic which is right on and the truth is so [...]

By: Paul

Paul — Sat, 31 Mar 2007 01:20:17 +0000

Most blog spam bots are very stupid. I have done (non-scientific) experiments on them, looking for an effective way to reduce spam WITHOUT causing an additional hassle to the user. My experiments confirmed what I thought – most bots do not even read the form, so filling a hidden field with a secret is enough to stop them. The ones that do read the form don’t execute javascript, so filling another field with javascript will stop them.

I have created a wordpress plugin based on my findings, it can be found here: http://www.paulbutler.org/archives/preventing-comment-spam-with-javascript-bot-detection/

By: aardvark

aardvark — Wed, 21 Mar 2007 05:15:43 +0000

to the other tyler:

just because they are not perfectly fluent in english doesn’t mean they have nothing worthwhile to say. there’s also cultural differences to worry about, what with all the different dialects of english in different countries.

By: Tyler

Tyler — Wed, 21 Mar 2007 02:04:43 +0000

OkI’m the other Tyler

I’ve used the simple 5 character CAPTCHAs and had no problems (yet), but I was thinking of using human logic if they ever got out of hand.

I never thought about using RegExp to parse the question to figure out the answer. But then how many people might have troubles reading: two plus two equals ?

Now some of you have mentioned that it might be hard for those who do not have English as their primary language to read that type of question and understand it, but if your blog is majority in English, wouldn’t they want to respond in English? Though I did recently have to convert someone who asked me a question in Spanish, to English using Babelfish, but then I was only brought up with English.

I’ll stick to the character CAPTCHAs for now, perhaps mix it up a bit and use simple images? Like a house or a tree? *shrug*