Interoperability and Integration Finding Semantic Agreement

Francis Harvey
EPFL-IGEO-SIRS
CH-1015 Lausanne
francis.harvey@dgr.epfl.ch

POSITION

One of the more intriguing issues facing geography, GIS, and certainly open GIS environments is integration. Recent GIS research on interoperability opens perspectives on what I will call integrative interoperability. This term reflects the dynamic needs of information integration in heterogeneous environments. While a rather loose use of the term encompasses any action that merges two previously distinct elements, a more exacting definition that calls on the philosophical tradition of British empiricists going back to John Locke, narrows integration to the process of integrating parts essential to the completeness of the whole. Distinguished from essential parts, integral parts are not necessary, but parts without which the thing would not be as complete and entire.
A useful analogy may be made to the human body. If we consider the whole human body, than the removal of arms leaves just a body. Only through the arms does the body possess the anthropomorphic qualities that make the human body an integrated whole. Geographers have sought fulfillment of this ideal for millennium. Most idiographic studies of geographic regions offers a wealth of rich examples from a wide range of approaches seeking to integrate observations of places into a coherent whole. Systematic geography sought to integrate as well in various, more mechanistic, ways. GIS continued this particular development in analytical cartography through the use of overlay to integrate various themes (Harvey, 1996). Now interoperability, complementing these approaches with strong computational and information processing backgrounds, copes with similar issues.

In modern geography, the fundamental concept of integration has been tackled in numerous ways. Too wide ranging to review here, I focus on the gap between mechanistic and holistic approaches. In mechanistic approaches, integration is the summing of separate parts. Geographers from holistic backgrounds understand integration as the unification of constitutive relationships. In other words, for the holistic tradition in geography, the whole is more than the sum of the parts (Harvey, 1997a). There have been some attempts to combine these perspectives, but without much effect. Recent work on the construction of scientific knowledge and technology provides some insight that links the constitutive relationships to the separation of parts in mechanistic approaches (Agre, 1992; Callon, 1980; Latour, 1987; Latour, 1993; Pickering, 1992; Star, 1995; Suchman, 1987). This work is especially important because it transcends the mechanistic/holistic dichotomy that has encumbered geography.


Integration remains an unwieldy concept because this dichotomy results in a vagueness and vast range of conflicting interpretations. Understandably, it has remained a qualitative concept. We apply geo-statistical measures to indicate the conformity, simple probability, or in Bayesian logic, the conditional probability, of a combination of different attributes. These offer insights into the similarity of attributes and their spatial arrangements, but don't indicate by themselves whether they are integrated. Determining the integration of geographic entities remains an act of human interpretation. Clearly, to turn integration into a manageable concept in terms of interoperability, it is necessary to address these open questions from an empirical perspective. This work sets out to provide the basis for semantically stable automatic integration processing.

All human activities are dynamic and this work on integrative interoperability rests on a foundation that accounts for the social diversity of geographic activities and the use of geographic information technology. Geographic integration is not the Fordist production of spatial widgits. It is the localized, socially contingent, dynamic process of knowledge production. Dependent on the social groups involved, it is contingent on their acceptance, and subject to their rejection. Situated integration cannot be planned, it is the result of actions in a distinct set of circumstances. Integral to this process, the computing technologies involved in geographic integration and interoperability transform the basic patterns of knowledge acquisition, use, the interaction with humans and machines, and the the very actions involved in producing meaning. Models for integrative interoperability need to rest on a conceptual foundation that considers both the humans and non-humans involved.

In the dynamic processes of interoperability, geographic integration is a matter of finding semantic agreement. This is not the technical agreement between exchange protocols, but a situated understanding between people involved that the results of an operation are integrated. They should have guidelines to evaluate their decision-making, but no plan can deal with all the contingencies the integration of geographic information raises.

Linking geo-statistical methods with holistic concepts is fundamental to broaden geographic integration to encompass open, highly heterogeneous computing environments of interoperability. Upon the technical foundations that exist, robust specifications that take into account the semantics of information exchange could be built. This is certainly an objective, not something immediately possible, but requiring research on constraints and possibilities for sharing geographic information. At present my goal is the formulation of guidelines for case-by-case application and refinement.

The work I have carried out on boundary objects and geographic information system design touches important parts of these issues (Harvey, 1997b; Harvey & Chrisman, in press). The semantical issues of sharing geographic information are broad and still require much work. The issues connected to integrative interoperability require a rigorous formalization around a concept I refer to as situated integrity. This paper defines this concept and takes a step towards its practical refinement.

Integrative interoperability is described in terms of situated integrity. This concept draws on GIS literature on error and accuracy (Chrisman, 1982; Chrisman, 1987; Goodchild, 1996; Veregin, 1989). On this background, I extend these measures to help quantify integration operations. The linkage of statistical measures with semantics is crucial to developing morphisms and formalizations for open data processing. Furthermore, the concept of situated integrity requires a rigorous description that reflects the integration of multiple social and spatial aspects.

Integrative interoperability in open processing environments requires the due consideration of the situatedness of GIS processing. This integration reflects the dynamics of the social groups involved, at the same time providing the technical basis for new forms of interaction. Considering semantics in terms of dynamic processes is the basis for integrating geographic information in the context of its use.

REFERENCES

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