Uyechi presents an extremely thorough and formal empirical description of the various features of ASL signs, of interest to any theoretician in developing a theory of sign phonology or in testing claims in the theory of the phonology of spoken languages against data from a signed language. The author also presents a formalism for representing signs and makes a number of theoretical proposals based on formalism. The volume's analysis indicates that the properties of core constructs of the spoken language phonology, namely the segment and the syllable, differ from the properties of the core constructs in a formal framework of visual phonology.