Frontmatter -- Signs, search and communication: Towards an empirical future for semiotics / I. SIGNS AND REPRESENTATIONS -- Semiosis, cognition, interpretation / A triadic theory of perception / Systems of logical representation and inference: An empiricist approach to cognitive science / Semiotic primitives and conceptual representation of knowledge / Semiotic aspects of neurally based representation of knowledge / II. ABDUCTION AND REASONING IN EXPERT SYSTEMS -- Human-like reasoning under uncertainty in expert systems / Abduction: The creative process / Expert systems and the abductive circle / Can machines compensate for biased human reasoning? Case studies in medical decision making / Procrustes, or the future of flexibility / III. COMMUNICATION WITH EXPERT SYSTEMS -- Believing, causing, intending: The basis for a hierarchy of sign concepts in the reconstruction of communication / On knowledge representing interacting systems / Implementing a sense of time in intelligent systems / Towards an evaluation tool for Natural Language Interfaces / The linguistic analysis of expert texts / Cooperative human-machine reasoning: Communication through the user interface / Name index -- Subject index -- Addresses of the authors -- Backmatter