On 28 February 2014 18:29, Brad Jorsch (Anomie) <bjor...@wikimedia.org>wrote:
> On Fri, Feb 28, 2014 at 12:07 PM, Mansi Gokhale <gokhalemans...@gmail.com > >wrote: > > > Then there's the issue of different interpretation. Take for example > https://www.mediawiki.org/wiki/File:Find-all-captcha-idea.png. Is the > second image wearing glasses? Or is that a lorgnette or something like > opera glasses, both of which are held in front of the eyes rather than > worn? > > https://www.mediawiki.org/wiki/File:Find-the-different-captcha-idea.pnghas > a similar problem. The first image is the only one with a cigarette, and > the only one with non-realistic coloring. The second is the only bald one, > and the only one with something resembling a lorgnette, and the only one > not looking in the general direction of the camera, and the only one with a > book. The fourth is the only child. The sixth is the only obvious female > (I'm not sure about the cat). The eighth is the only one smiling, and the > only one with visible teeth. > I think this is oversimplifying. Of course some people can interpret a picture puzzle in slightly different ways - the whole *point* of a captcha is to distinguish between the intuitive reasoning of a human and the formulaic reasoning of a computer; if there was absolutely no ambiguity, it would be a very poor captcha. In exactly the same way that the letters on a captcha will sometimes be distorted in such a way that humans genuinely make a mistake, sometimes the questions in a picture puzzle can be sufficiently distorted to the point that they are answered incorrectly. The 'difficulty' of *any* captcha obviously needs to be carefully calibrated to hit the sweet spot between mundanity and ambiguity. But putting out nine pictures of humans and one picture of a cat and asking for the "odd one out" is no easier to misinterpret than a squiggle that might be a G or might be a 6. --HM _______________________________________________ Wikitech-l mailing list Wikitech-l@lists.wikimedia.org https://lists.wikimedia.org/mailman/listinfo/wikitech-l
