Definition: Graduated symbols
UN - Geographic Information Systems
In thematic cartography, the use of symbols (e.g., circles or squares) to represent the magnitude of a variable at a point or in a reporting unit. The size of the symbol is proportional to the value of the variable.
United Nations, "Handbook on Geospatial Infrastructure in Support of Census Activities", Department of Economic and Social Affairs, Statistics Division, Studies in Methods, Series F No. 103, New York, 2009