Chapter XVI
GENERAL METHODS
There are a number of comparatively little known short cuts
and convenient methods available in the collection and recording
of statistical facts. If obsolete or unsuitable methods are
used it may make a difference between success and failure in the work
of keeping records of any complex business. When the methods of
tabulation are too laborious, not only are the records so extensive as
to be in disfavor, but they may occasionally include errors, in spite of
the greatest care that can be taken by even the highest grade of employees.
Anything which will reduce the amount of mental concentration
necessary on the part of persons collecting and tabulating facts, will
ordinarily assist in the production of more accurate final results. In
large statistical studies, such as are made by the United States Census
Office, it would be practically impossible to get all the information
now obtained if tabulating machinery were not brought to the aid of
the human brain and hand.
The punched-card system now widely used in statistical work has made possible an almost unlimited amount of subdivision of analysis with very little extra expense. Fig. 228 shows the card used by the United States Census Office for the 1910 census. One of these cards was punched for each inhabitant in the United States in accordance with the data obtained by the Census enumerators. It will be noticed that the card contains different columns of names or numbers and that there are twelve classifications possible in each vertical column in which a punched hole may be made. Ordinarily the different columns are used for different subjects, and the position of the punched hole in each column records the classification of the data relating to that particular subject.
The punched cards are stacked so that all are right-side up. It will be noticed from Fig. 228 that the lower right-hand corner of the card