Modeling evaluation of the size of countries (regions) using fuzzy logic

Countries (regions) size rating is based on various parameters: area, population, population density, economic development (GDP, GDP per capita etc.), natural resources, markets, etc. The most common rating is based on the area of the country (km2). The values defining at the transition between the levels (classes), has a large level of subjectivity present, and the classes are more often contradictory. Countries classification as 'Small', 'Medium' or 'Large' more often is subject for discussions and mutual disagreements. Fuzzy logic is a superset of conventional (Boolean) logic that has been extended to handle the concept of partial truth - truth values between 'completely true' and 'completely false'. As its name suggests, it is the logic underlying modes of reasoning which are approximate rather than exact. The importance of fuzzy logic derives from the fact that most modes of human reasoning and especially common sense reasoning are approximate in nature. This paper presents a model for size evaluation of countries (regions) using Fuzzy logic. Input and output variables are defined. Input variables are: area, population and population density of countries (regions) and the output variable is the size evaluation of the country (small, medium or large).