Spot map is used for -

Studies of the geographical distribution of disease is one of the impoant dimensions of descriptive epidemiology. These variations include International variations, National variations, Rural-urban variation and Local distribution. These variations are best studied with the aid of 'spot maps' or shaded maps. these maps show glance areas of high or low frequency, the boundaries and pattern of disease distribution. Ref: 25th edition, Park's Textbook of Preventive and Social Medicine, Page no. 74