Clutter Reduction Methods for Point Symbols in Map Mashups

Map mashups are often visually chaotic and methods for solving this chaos are required. We introduce a set of clutter reduction criteria for evaluating methods to reduce clutter in map mashups. We present a synthesis of cartographic generalisation operators for point data and clutter reduction methods used in information visualisation and evaluate the methods against the criteria. The resulting evaluation table can be used in finding suitable clutter reduction methods for cases of map mashups with different primary criteria, and more specifically in finding methods that cover each others’ limitations.