Improving on CAPTCHA

As CAPTCHA proves susceptible to spammers (OCR-based software can crack CAPTCHAs) better ways of keeping out bots are being researched, for example replacing the CAPTCHA task with graphic or image-based tasks, such as drawing round the outline of a specific image or giving a group name to a set of pictures. According to this Computer World review a key difficulty is finding tasks and task descriptions that enable users to understand rapidly what is required of them. To quote: 'These tests do have their shortcomings. For starters, what is clear to the designers may not be clear to users.'

Via Mindhacks