The dummies are partially based on Slappy the Dummy. George is a ventriloquist and has a wooden giraffe ventriloquist dummy named Wally. This is referred to as the dummy variable trap. The coefficients attached to the dummy variables are called differential intercept coefficients. He then called in Knight, who made a single dummy run before releasing his bomb. Sometimes it was the presenter who acted as test dummy. Thus, it is necessary to encode only three of the four possibilities as dummy variables. This avoids the need for any dummy table. A related concept in statistics is that of a dummy variable. He turned his hotel room into a gym, practicing with weights and a wooden dummy. Unlike dummy coding, there is no control group. Older versions of the Wing Chun wooden dummy were originally placed in the ground. Eminem being used as the dummy in the scene. It was later retrieved by police and determined to be a harmless dummy. An alternative to Xvfb is Xorg with dummy devices.