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Index (CEPHALIC CRANIAL PELVIC terms)

CEPHALIC, CRANIAL, PELVIC, terms used to designate the proportions of parts of the body or of a skeleton, employed especially by anthropologists in determining racial groups. The most commonly used index is the ratio of the width of the head to the length, known as the cephalic index when applied to living beings, and cranial index when applied to the skull. The length of the skull is taken just above the eyes where the forehead protrudes most, while the width is taken at any part of the head having the greatest breadth.

The metric system is used in all measurements. Tables of index numbers have been compiled so that indices may be determined without actually working out the accepted formula,-Width x 100 -=1.

Length Heads may be classified also according to indices other than those of length and breadth of the skull:-facial, nasal, dental, and pelvic being often used. The cephalic index does not always give accurate information, because it is taken only on the upper part of the head, and is not a sufficient guide to the shape of the head as a whole. Heads having an entirely different cross sectional outline would fall into the same class by this method of measurement, so it can be taken as an exact guide only when a large number of skulls of the same race are observed to give the same result.

INDEX NUMBERS are used by economic statisticians to measure the amount of change that takes place in the value of money, as shown in its relative purchasing power. It is obvious that money itself could not be used as the measure of its own value, nor could any one commodity which would be purchased with a fixed sum of money be used, since single commodities fluctuate in value even more than money. However, the average price fluctuations of a number of different commodities show INDEX PROHIBITORIUS very clearly the amount of change that has taken place in the value of money.

These totals of average prices for a year form the basis of comparison for variations, and are called index numbers. The averages, to be exact, must be "weighted," which consists of giving commodities different degrees of importance, since in a list including potatoes and fountain pens, the potatoes should of course be given a higher weight, because more money is spent on them than on fountain pens.

In the United States the Bureau of Labor, Bradstreets, and Babson's compile and publish index numbers, while the "London Economist" and the British Board of Trade are the leading English authorities, all of which usually agree about the general trend of prices.

Because of the greater ease with which prices may be collected and because of the more general standardization of quality, the wholesale prices are used in computing the index numbers. The average may be computed harmonically, geometrically, or the simple unweighted arithmetic average may be used. The later method, if done intelligently, produces results which do not vary greatly from those obtained by the more elaborate methods.