Geoscience Reference
In-Depth Information
- Challenge 1:
to build the empirical objects
corresponding to the conceptual
objects identified as relevant relative to the thematic questioning: it means
comparing the objects (as well as their properties and the associated relationships)
that have been identified from a conceptual point of view (see Chapter 1) with the
information that is observable from an empirical point of view. The objective is,
therefore, to build the empirical entities that would be the most faithful possible to
the conceptual representation that was made. We will focus on the entities of spatio-
temporal nature;
- Challenge 2:
to represent and explore the changes and movements
2
performed
at the level of these objects, in particular the changes in their properties and in the
associated relationships: the purpose is to show and make these changes and/or
movements explicit and to build different representations (calculated and/or
visualized) by querying the database. This challenge is related to the domain of
database queries, visualization and interactive exploration;
- Challenge 3:
to identify and analyze the evolution of relationships
between the
objects' properties (or in other words, of the correlations between the attributes or
the indicators characterizing the objects) or of relationships between the objects. It is
a matter of building new indicators that allow testing assumptions about the
organization of the phenomenon being studied (in terms of spatial differentiations,
of exchanges between places, etc.). This challenge refers to statistical analysis and
spatial analysis methods;
- Challenge 4:
to identify the processes underlying change:
the idea is to
formalize models that bring into play the factors considered as driving forces in
change and to implement them in a computing environment. It allows simulating the
emergence and the dynamics of the phenomenon being studied and testing different
scenarios. This challenge involves computer simulation.
Each of these four challenges implies modeling. But the models associated are in
general of a different nature, data models, statistical models, spatial analysis models
and simulation models. Some of these models will have a more descriptive objective
(data models and statistical models), other more explanatory (statistical models and
simulation models). In some cases, these four challenges will succeed one another in
a linear manner following the stages of a study or research. In other cases, the
approach is based on round-trips. The same model can even be used at different
stages, with different objectives. A classic spatial analysis model, such as the gravity
model, can for instance be used to verify that the intensity of exchanges between
2 It should be noted that movement may be regarded as a particular type of change, that of the
change of location of a mobile object. Movements and changes are in general treated
differently in the literature, because they raise different questions in terms of time and space
(for example, the same methods are not mobilized in order to study change in a territory or the
mobility of a person), and we choose to respect this dichotomy.
