Source Texts
Text
One challenge faced by researchers studying global urbanization is that different countries have different definitions of what constitutes an urban settlement. Many countries define urban settlements based on the number of people living in them. However, countries do not all use the same number to define an urban settlement; for example, Iceland uses a minimum population of , while Mali uses . Other countries use a combination of population and other factors, like the number of buildings in the area. This variation makes it difficult for researchers to compare aspects of urbanization in different countries.