Cognitive Evidence of Vagueness Associated with some Linguistic Terms in Descriptions of Spatial Relations

Abstract

When describing spatial relations, humans often use qualitative linguistic terms. For example, it is fairly common for people to say "Region Q covers Region R a little bit." Unfortunately, current Geographic Information Systems (GIS) do not have the intelligence to directly represent and process linguistic descriptions containing qualitative linguistic terms such as 'a little bit,' 'somewhat,' 'nearly completely,' and 'completely.' An important step in developing more natural GIS that can process natural language-based queries is to quantify these qualitative linguistic terms. The purpose of this study is to find out how much of Region Q is covering Region R if "Region Q covers Region R a little bit, somewhat, or nearly completely" through experiments with people. Based on the experiments, it is concluded that (1) if the ratio between the area of region R covered by region Q and the area of region R is 0.50 or less, then one usually says "Region Q covers Region R a little bit," (2) if the ratio is greater than or equal to 0.15 but less than 0.70, then it is somewhat, and (3) if the ratio is greater than or equal to 0.55 but less than 1.00, then it is nearly completely.