From Big Medical Encyclopedia

CARTOGRAM — the schematic contour map of the area, on a cut shading or various shades of the same color represent various levels (sizes) of any phenomenon.

To. are applied to the evident image of prevalence (intensity) of the phenomenon, including and in medical statistics. Technology of creation To. following: 1) from the indicators characterizing prevalence of the phenomenon (e.g., any disease) in various districts, form a variational series (see. Variation statistics ) as increase of size of an indicator; 2) determine the maximum and minimum sizes; 3) the received difference is divided into 4 — 6 equal parts; 4) each of these parts is given a certain type of shading or a shade of paint with strengthening of its intensity in process of increase of size of an indicator and paint over or shade on the map certain areas with the shade of paint corresponding to the size of an indicator or type of shading. E.g., at blue color shades from pale blue to dark blue are given, at yellow color — from light yellow to dark brown. In the absence of this phenomenon in this or that area the site of the card remains not painted over (not shaded). On each area there has to be its name or number which is deciphered sideways To. in the special list. Use shading in case of impossibility to apply paint, at the same time shading can be various intensity.

Kartodiagramma — subspecies To. — the image of the chart on the map. The column with height equal to the size of the interfaced factor, or a circle (the sector chart) is located on the schematic contour map in each area. The combination is possible To. with the chart. E.g., on To., to the short-sightedness representing prevalence among school students in various geographical districts of the country, it is possible to show in the form of columns or sectors of a circle security of schools with rational furniture and illumination of educational classes.

Bibliogr.: See bibliogr, to St. Graphics .

E. L. Notkin.