This paper, in reviewing four different studies, discusses the influence of some basic parameters or aspects of a sign on the accuracy of perceiving that sign. This information can aid the teaching of signs to the mentally retarded, the autistic, the cerebral palsied, and the hearing adult. A series of studies was conducted in which the aim was to control (eliminate), as directly as possible, the given parameter on which interest was focused. In the case of location in reference to the body, the face, body, arms, and legs were eliminated from the picture. Movement was controlled by holding the hands still. Handshape was controlled by first using only one basic handshape and then by using rather formless mittens. Findings indicate that the method by which data about sign parameters are collected very markedly affects results. In terms of the various studies, conflicting results include: (1) parameter effects are sign specific, (2) movement is the most important parameter, and (3) movement is the parameter least influential on recall. (JK)