\input zb-basic \input zb-ioport \iteman{io-port 02000418} \itemau{Garc\'{\i}a-Cabrera, Lina; Rodr\'{\i}guez-F\'ortiz, Mar\'{\i}a Jos\'e; Parets-Llorca, Jos\'e} \itemti{Toward a formalisation of evolutionary hypermedia systems based on system theory.} \itemso{Moreno-D\'{\i}az, Roberto (ed.) et al., Computer aided systems theory - EUROCAST 2001. A selection of papers from the 8th international workshop, Las Palmas de Gran Canaria, Spain, February 19-23, 2001. Revised papers. Berlin: Springer. Lect. Notes Comput. Sci. 2178, 270-284 (2001).} \itemab Summary: Main development and use activities of Hypermedia-Systems evolve through time. Hypermedia-systems need models that support the evolutionary nature of their building, maintenance and navigation processes. The System Theory and cognitive models offer a better perspective of web-systems and succeed in abstracting their structure, information and behaviour. We assume that an Evolutionary Hypermedia System must be modelled by means of a set of interrelated and interacting systems that allow: a) from the author's viewpoint, complete and flexible control of the development and maintenance of hyper-documents; b) from the reader's point of view, an understandable navigation that allows easy access to and selection of information. The Model allows an explicit representation of the semantic content which allows us to structure the information-system and determines its possibilities of change, updating and evolution. In addition, the model is flexible enough in offering the necessary mechanisms to incorporate and represent the author's conceptual-domains in order to characterise the information-domains. \itemrv{~} \itemcc{H.4 H.5 I.2.1} \itemut{} \itemli{http://link.springer.de/link/service/series/0558/bibs/2178/21780270.htm} \end