may be represented either as 
linear features or as polygons; 
insufficient information in the 
linear feature would make it 
impossible to determine the two 
sides of the river. 
An effective information exchange system 
could exchange information between 
GIS’s. It might even be able to rebuild 
lost information. It could not replace 
information that is not deducible from the 
data. 
CONCLUSION 
Effective information exchange takes place 
at the application entity level rather than at 
the data format level. Both data translators 
and standard formats address the problem 
at too low a level to be effective. 
Information exchange requires a data 
dictionary, knowledge of the GIS construct 
and, in addition to an ability to read the 
data format, an appreciation of the data 
models. Until the problem is realistically 
addressed at the proper level, the 
frustrations of converting data between 
systems will not be effectively resolved.