I would like to offer some additional information for consideration. All accessibility problems of traditional CAPTCHA solutions and individual pitfalls are described very thoroughly, but there are also new CAPTCHA solutions on the market that resolve many of those issues.
Language agnostic: Instead of using spoken numbers or words, the audio CAPTCHA uses sounds that the user is asked to identify. Identifying sounds requires less cognitive overhead compared to transcribing spoken text. Also, it easily caters for a global audience provided the user interface itself is extensively localized.
No distortion: Such sounds are also less prone to automated solving compared to speech, which in turn allows the audio to be less distorted thus easier to identify for the user.
Fully integrated audio player: Playback can be paused, resumed, and repeated unlimited number of times without changing to a new CAPTCHA, timing out, or the need for downloading audio files.
General accessibility-friendly characteristics design principles
Users are always given the choice between an audio or image based CAPTCHA. Users are free to swap at any time, even repeatedly.
Both variants support various assistive technologies and strive to follow a11y best practices.
Imposing no time limits on providing an answer; allowing unlimited number of retries; using simple verbiage/imagery/concepts; providing solve hints (some of these points with potential exceptions in case of high threat profile)
Using lowest possible friction (incl. showing no interactive CAPTCHA at all, up to 95% of all site traffic), then stepping up the friction depending on the threat profile of a given user request.
Background
)* For transparency: I am PM at Arkose Labs, who offers solutions for fraud and abuse mitigation - an interactive CAPTCHA is part of our toolbox. Over the past couple of years, many large corporations such as Microsoft, Amazon and many more, have switched away from reCaptcha and other traditional CAPTCHAs to our solution not least because of the better accessibility (as well as better security).
I’m not trying to market our solution here - but I strongly believe that it’s possible to make an accessible CAPTCHA at least to WCAG level AA. (In fact, the Arkose Labs audio challenge is already WCAG certified - the rest of our solution hopefully soon to follow - we’re investing heavily in that area). The accessibility topic was the main driver for Arkose Labs to join W3C just recently - to learn from the community and improve what we do, and to share the path we're currently on.
Summary
I would appreciate if the article could touch on some of these more positive examples outlined above. And maybe even consider rephrasing the title “Inaccessibility of CAPTCHA” to something that sound less like a conclusion, and more like the comprehensive in-depth evaluation that it is.
I would like to offer some additional information for consideration. All accessibility problems of traditional CAPTCHA solutions and individual pitfalls are described very thoroughly, but there are also new CAPTCHA solutions on the market that resolve many of those issues.
Example: Arkose Enforce *
Sound Output
General accessibility-friendly characteristics design principles
Background
)* For transparency: I am PM at Arkose Labs, who offers solutions for fraud and abuse mitigation - an interactive CAPTCHA is part of our toolbox. Over the past couple of years, many large corporations such as Microsoft, Amazon and many more, have switched away from reCaptcha and other traditional CAPTCHAs to our solution not least because of the better accessibility (as well as better security).
I’m not trying to market our solution here - but I strongly believe that it’s possible to make an accessible CAPTCHA at least to WCAG level AA. (In fact, the Arkose Labs audio challenge is already WCAG certified - the rest of our solution hopefully soon to follow - we’re investing heavily in that area). The accessibility topic was the main driver for Arkose Labs to join W3C just recently - to learn from the community and improve what we do, and to share the path we're currently on.
Summary
I would appreciate if the article could touch on some of these more positive examples outlined above. And maybe even consider rephrasing the title “Inaccessibility of CAPTCHA” to something that sound less like a conclusion, and more like the comprehensive in-depth evaluation that it is.