Glossary A to D
application framework
We describe the EMDS system as an application framework, in part at least, because it does not come "ready to run out of the box." Instead, the system provides a very general solution method (e.g., a framework) for conducting environmental assessments. In order to conduct an assessment with EMDS, the user constructs a data catalog that identifies the sources of all GIS themes that can enter into an assessment, and constructs a knowledge base that describes the relations among all the ecosystem states and processes of interest to the assessment.
EMDS includes tools for both of these activities. In particular, the ArcView system includes utilities for creating and editing the data catalog, and the NetWeaver development system provides a knowledge base development environment.
Although the EMDS framework approach requires the user to build the data catalog and the knowledge base, there are also two very significant advantages:
- The topics to be included in an assessment, the relations among ecosystem states and processes in the knowledge base, and the sources of data are completely determined by the user. In other words, the user has complete control over problem definition.
- Assessment applications can be developed somewhat generically for a larger region, and then easily customized for specific subregions.
Assembling the data catalog should require about 4 to 8 hours, assuming the data bases for the assessment already exist. Simple knowledge bases can be built in a few days. More complex knowledge bases may require a few weeks to construct.
dependency network
A dependency network represents knowledge about how to solve a problem (in our case, how to evaluate topics of interest in an assessment) in terms of the topics of interest in the problem domain, and the relations (dependencies) among these topics.