The dream of technology is to improve our lives — to correct our human failings and to make us better than we were. The possibilities of technology could be particularly fruitful for the lives of individuals with disabilities. So why do we cling to CAPTCHA, a technology that actively impedes access to the visually impaired?
The backlash against CAPTCHA isn’t necessarily motivated by outrage over accessibility issues. It often just stems from ordinary frustration. When you’re filling out a form — often a tedious process its own right — the last thing you want to do is struggle with a computer trying to determine if you’re human or not. Staring into strings of wavy nonsense words, letters, or numbers embedded into images have become a staple of the internet.
But while CAPTCHA is a source of frustration for your average John or Jane User, the system can be downright prohibitive for individuals with certain disabilities. Image-only CAPTCHA systems, for example, often bar visually impaired from whatever feature the CAPTCHA is gatekeeping.
This technology is so restrictive that groups are even organizing against CAPTCHA. This past summer, the Australian Communications Consumer Action Network, along with other consumer rights groups, called for an end to CAPTCHA. They requested, in no uncertain terms, that the CEOs of top companies such as Google, Microsoft, Twitter, and Facebook (among others) stop using CAPTCHA in favor of other, non-discriminatory ways of combating spam.
Modifications to the current system are also insufficient. More and more CAPTCHAs do feature an audio option, but they are not a solution. These alternatives are often considerably more frustrating than even the image CAPTCHAs. Users are often left listening to distorted sound clips that seem to come straight from a horror movie and can be just as — if not more — aurally unintelligible as CAPTCHA images are visually unintelligible.
A Stanford University study published in 2010 found that even in the clearest audio CAPTCHAs, users were only able to agree on one distinct answer (as opposed to two or three distinct answers) in 30% of the cases. Some CAPTCHA systems, like Google’s reCAPTCHA audio version, fared much worse. Only about 1% of the CAPTCHAs had one distinct answer while 90% had at least three distinct answers. In these instances, CAPTCHA isn’t just frustrating, it’s prohibitive.
For instance, in a moment of tragic irony, the US National Federation for the Blind says its members were unable to sign an E-petition calling for printed materials to be more accessible to the visually impaired on the White House website because of CAPTCHA security.
The solution won’t be found trying to salvage a broken system. At its core, the CAPTCHA is a reverse Turing test or a computer capability that must be able to ascertain with a high probability the difference between a human and another computer. Nonetheless, there are other ways of differentiating the human from the machine now that machines language capabilities — both in reading text embedded into images and in recognizing speech in audio — have improved. And even Turing tests themselves will fail to combat human spammers.
Instead, we should explore other ways of addressing our spam problem, preferably ones that do not add an extra step to any form. Systems that analyze the behavior of a user filling out a form or other technical parameters could be a means of discerning human from machine and of differentiating between honest attempts to access a webform and spam in a way that doesn’t require an extra step for the user and is accessible to everyone.
Julia Fominova is the CEO of Keypic, creator of spam detection in web forms using expert systems.