Captcha verifications are not that hard, just type the characters you see in the box in the field provided, right? Well I can’t do it. My success rate is seriously less than 50%. And it’s not that I’m a bad typist (actually, I’m a good typist—ask recently avid reader and commenter Ralph, who astutely pointed out that what I do on this blog is called typing). It’s just that for some reason what I see and type is not what the captcha supposedly displayed.
Which begs all sorts of unanswerable science/philosophy-type questions, such as is what I see as blue the same as what you see as blue, or is it more like your red?*
*Actually this whole notion of whether what I perceive as blue could be your red doesn’t make much sense. Which is not to say that the perception of colors is fixed—there’s certainly enough variation within the structures of the eyes and brains of various humans that the way colors are perceived may not be and is likely not perfectly consistent from one individual to the next. But any variances seem most likely to be a shift rather than a transposition. Colors are the perception of wavelengths of light. The wavelengths don’t vary, but how we perceive them likely does to a certain degree, so while a yellow to me may be closer to what I see as orange to you, it’s highly unlikely that my orange will be your purple and vice-versa. Or at least that’s my half-baked theory from having given this very question a certain but not very thorough or verifiable degree of thought.
Except in this case, it’s a question of whether what I perceive to be certain letters are actually the letters displayed, and if not, how on earth I can successfully do things like read books or write highly-engaging and entertaining (sure to be bestsellers were they not proprietary and confidential) software functional specifications and user documentation.
I recently posted an ad on Craigslist for a wheelset I’d like to sell, and it seriously took me four attempts to get the Captcha phrase correct. From now on I’m going to start clicking on the accessibility link and have the digital voice read to me rather than making another one of my consistently inaccurate guesses as to what combination of characters is supposed to have been displayed.