found: Glossary of the mapping sciences, 1994:map, thematic (a map whose principal purpose is depicting information other than that about the Earth's physical surface. Also called a topical map. Among the kinds of information shown on thematic maps are density of population, kind or amount of crops grown, types of soil, amount of rainfall and administrative subdivisions)
found: LCSH, Dec. 7, 2009:(hdg.: Thematic maps)
found: University of Kansas. Institute for Social and Environmental Studies. Choropleth map of 1969 Kansas population by county, 1969.
found: Mersey, J.E. Colour and thematic map design : the role of colour scheme and map complexity in choropleth map communication, c1990.
found: ODLIS: online dictionary for library and information science, Dec. 11, 2013(choropleth map. A thematic map on which color, shading, hatching, or some other graphic technique is used to show the density or frequency of a quantifiable variable (e.g., population, mortality, precipitation, etc.) in each of several administrative or enumerative areas, based on average number of occurrences per unit of area, usually divided into classes.)
found: Wikipedia, Dec. 11, 2013(Choropleth map. A choropleth map is a thematic map in which areas are shaded or patterned in proportion to the measurement of the statistical variable being displayed on the map, such as population density or per-capita income. The choropleth map provides an easy way to visualize how a measurement varies across a geographic area or it shows the level of variability within a region. A special type of choropleth map is a prism map, a three-dimensional map in which a given region's height on the map is proportional to the statistical variable's value for that region.)
