reCAPTCHA

reCAPTCHA is a CAPTCHA-like system designed to establish that a computer user is human (normally in order to protect websites from bots) and, at the same time, assist in the digitisation of books.

reCAPTCHA is a free service that protects your site from spam and abuse. It uses advanced risk analysis techniques to tell humans and bots apart. The users need to make a single click to confirm they are not a robot. This is Google authored code that provides plugins for third-party integration with reCAPTCHA.

reCAPTCHA is a reversed CAPTCHA – the same test, used not only to prevent spam but to help in the book digitazion project. In other words, the reCAPTCHA tests are not meaningless combination of words, but excerpts from books that undergo digitation, while the general CAPTCHA uses several human validation methods including math or general knowledge questions, visual puzzles and even chess puzzles.