A new theory of sign structure is proposed which explains the syntactic, semantic and pragmatic classification of signs. The theory comprises in part a language capable of relating studies of information processes across a range of disciplines, including communication science psychology, computer science, and linguistics. The power and utility of the theory and the language are illustrated by explicating empirically such syntactic and semantic processes as perception, syntactic communication, and memory coding. The report indicates the relevance of the theory to selected applied problems of information engineering. The development and activities of the SEMLAB, a semiotic research laboratory dedicated to empirical investigations of information phenomena, are described. (Author/AP)