@ARTICLE { Rsds51,
author = {Duckham, M. and Mason, K. and Stell, John G. and Worboys, Michael}, 
title = {A formal approach to imperfection in geographic information}, 
journal = {Computers, Environment and Urban Systems}, 
number = 	{(no. 1,1)}, 
volume = 25, 
pages = {89-103}, 
publisher = {Elsevier Science Inc.}, 
address = {Amsterdam, The Netherlands}, 
month = {January}, 
year = 2001, 
abstract = {Traditional computational models of geographic phenomena offer no room for imperfection. Underlying this tradition is the simplifying assumption that reality is certain, crisp, unambiguous, independent of context, and capable of quantitative representation. This paper reports on initial work which explicitly recognises that most geographic information is intrinsically imperfect. Based on an ontology of imperfection the paper explores a formal model of imperfect geographic information using multi-valued logic. The development of Java software able to assist with a geodemographic retail site assessment application is used to illustrate the utility of a formal approach.}, 
keywords = {imperfection, qualitative spatial reasoning, rough set theory (RST), vagueness, }, 
}