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by Dr. Waldo Tobler

Dr. Tobler describes the areal interpolation technique he deve-loped to permit the construction of density, or contour maps, from data arranged by area. Such data, which may include information about geographical units such as school districts or neighborhoods, are common in the social sciences, but
present special problems for cartographers. Dr. Tobler's tech-nique provides social scientists with a means of resolving these problems.

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