A theory of contexts in information bases

Abstract

Although semantic data models provide expressive conceptual modeling mechanisms, they do not support context, i.e. providing controlled partial information on conceptual entities by viewing them from di erent viewpoints or in di erent situations. In this paper, we present a m o d e l f o r representing contexts in information bases along with a set of operations for manipulating c o n texts. These operations support context creation, update, copy, union, intersection, and di erence. In particular, our operations of context union, intersection, and di erence are di erent from these of set theory as they take i n to account the notion of context. However, they also satisfy the important properties of commutativity, associativity, and distributivity. Our model contributes to the e cient handling of information, especially in distributed, cooperative e n vironments, as it enables (i) representing (possibly overlapping) partitions of an information base (ii) partial representations of objects, (iii) exible naming (e.g. relative names, synonyms and homonyms), (iv) focusing attention, and (v) combining and comparing di erent partial representations. This work advances towards the development o f a formal framework intended to clarify several theoretical and practical issues related to the notion of context. The use of context in a cooperative e n vironment is illustrated through a detailed example.

A context-based methodology for integrating Web 2.0 services in learning scenarios

“…Akaishi et al (2003) define it as a modular representation of information under different perspectives in their description of a framework for context-based generation of information access spaces. Same notion is repeated in the work of Theodorakis et al (2002) who define context as a cognitive container which encapsulates a particular information view. From an interaction design perspective, one context corresponds to one generic usage objective and encapsulates the interactive functionalities that correspond to this particular objective.…”

Model Continuity in Discrete Event Simulation

“…The context includes the purpose of the modeling process, information about the environment of the source system, and the constraints, assumptions and facts that affect the modeling process. A context can be formally defined in a model as well [Theodorakis et al 2002]. A model is specified in a modeling language [Milicev 2009].…”

Conceptual modelling of web information systems

“…A completely different direction of research is the work in [39,40] on contextual information systems (CIS), which provides a formal framework for the specification of contexts. One important use of contexts is to help WIS users not to lose track, while navigating through the WIS.…”

“…However, subtyping is a static concept, which is useful for tree-like navigation structures, whereas in some cases the more complex navigation and story structures will require a dynamic solution. We therefore ask, whether the work on contextual information bases (CIBs) [41,39,40] can be exploited for enhancing our methodology. We generalise and tailor the CIB-approach in order to integrate it with the theory of media types.…”