An automated test to tell computers and humans apart is disclosed, comprising displaying on a computer screen an animation comprising of a foreground and a background, one of the foreground comprising a plurality of typographical characters and the other comprising partial obstruction of the typographical characters, and wherein the animation comprises relative motion between the background and foreground. The automated test may comprise displaying on a computer screen an image, and requiring the user to perform operation on the image to resolve an encoded solution. The test may also comprise displaying on a computer screen a video clip, and requiring a user to provide an input corresponding to subject matter presented in the video clip.