CAPTCHA and the Non-Standard User

In the last year or so a number of sites that offer a service or interact with readers via comments have started using images as a way to authenticate users as living people rather than a piece of software. These CAPTCHA images reduce fraudulent accounts used for spam, spreading malware and engaging various other nasty practices. A Capcha image of a Google CAPTCHA sequenceis an image of a few characters (letters and numbers) without actual meaning, that are deliberately distorted so that a human is usually capable of deciphering them, but a piece of software is not. CAPTCHA stands for Completely Automated Public Turing Test to Tell Computers and Humans Apart. There’s a picture of one over there to the left, in case you’ve somehow missed them.

I think I first noticed them on Yahoo, but captchas have began appearing all over the place, in Google services account creation pages, on Blogger for comment posting, and in various blogging systems via plug-ins. The user sees the captcha, decodes it, and then types the nonsensical but short text string in a box to authenticate as a Real Live User. I’m sure using CAPTCHA to authenticate users reduces fraudulent accounts and spam comments.

But I can’t read them, most of the time. I suppose you could say I failed the Turing test. I’m dyslexic. My dyslexia rarely affects my reading, because while a b p and d might as well be the same letter, there’s context so I can figure out what the word is—and it’s not like I’m going to see b, p, and d in the same word all that often. I’m actually a good reader. Usually. Yahoo capchaBut captchas rarely use real words, they tend to mix letters and numbers, and they’re distorted spatially (which I do quite well on my own, thanks). In some implementations, captchas include extraneous data like “scratches” as well. More often than not, I can’t decode the image and can’t type the letters in the field, and so can’t authenticate myself as human.

That means, for instance, I may not comment on your blog. No big loss that. But what if you’re using CAPTCHA on an educational site, perhaps part of a LMS or class web site? What if the workplace uses Capcha for authentication for some services? Oops.

MIT, who created CAPTCHA, created a system of audio captchas; that is, a digital recording (usually a string of numbers) with a lot of background noise (say, burbling water, or “wallah”) and perhaps two voices providing the numeric string, and then inserting extraneous words. I have a hard time with those too, but at least Google thought to offer them; I can play the audio as many times as I want while I make a transcription. So far, Google is the only site I’ve seen using CAPTCHA that offers an alternative for those who can’t decode the image. There’s a useful Note on the Inaccessibilty of CAPTCHA from the W3C.

If you’re using CAPTCHA

  • Please provide a clear alternative for people who have difficulty.
  • Consider providing an e-mail address, where a user can introduce themselves and you can post their comment or create the account for them when they really can’t deal with the captcha.

Good for Apple

Apple has changed the way the MiniStore works; now you see this explanatory screen. The screen replaces the MiniStore area of the iTunes window, and explains what the MiniStore does, and how to turn it off. It states that “Apple does not keep any information related to the contents of your music Library” and asks if you would like to turn on the MiniStore now, with a button.

Much better Apple; thanks.

Weblog Usability

Jakob Nielsen posted an article on the top ten web log design flaws. Most of his suggestions were things I’ve been doing from the start, but two of them were new to me. He suggests a list of the “top posts,” or most popular posts; I’ve added a category on the side for that purpose, linking to the posts that show up most frequently in my referral logs. He also suggests a picture; that one, I’m still thinking about. It seems inappropriate to me, though I understand his reasoning, and I’m not qute sure how to place it in terms of layout. Maybe later.

Moving to the Big Screen

Since The Spouse has a brand-new one of these, I get the previous model, the gorgeous iMac G4 Flat-panel, still under Apple Care. I spent part of the weekend transferring data from my iBook, and setting up applications. I’ve been using my twelve inch iBook for most of my own work for so long, it’s dizzying to have more screen real estate; I really like it. I’m literally seeing things in new ways.

I already knew NetNewsWire 2.0 was a fabulous RSS aggegator, but the support for synching two copies of NetNewsWire via .Mac is totally cool. I can read RSS feeds, and subscribe to them, from the iBook or the iMac, then painlessly sych my subscriptions, read posts, even the open tabs, via .Mac, with a single menu item. Safari too, under Tiger, makes it very very easy to synchronize bookmarks between the two Macs.

I used Buzz Andersen’s nifty PodWorks to transfer my iTunes playlists and files from my iPod. Plus I discovered that Mellel has a new plug-in that supports Spotlight.