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The process of obtaining statistical data from documents not primarily designed for this purpose is called extraction1. Data may be extracted from documents mechanically2 by using tabulating machinery3 or punched card machines3.
To extract information mechanically it is first necessary to code1 the information on the basic document2. This process consists of the translation of the information into numerical form by means of code numbers3. The key by which this information is translated is known as a coding scheme4. Such a scheme limits possible sub-division of the data, but in the ultimate tabulation or breakdown certain codes may be shown in combination. A combination of individual codes may be called a classification5 (cf. 130-7*) where the information is shown under certain heads6 (cf. 110-2) or headings6.
- 1. code n. — code v. — coder n'., one who codes.
There are four fundamental operations in mechanical tabulation. Punching1 consists of the transfer of the information to a punched card2 sometimes called a punch card2. The information is shown on that card by punching a hole in a given position. Verification3 is the process of checking the accuracy of the punching. Sorting4 is the arrangement of cards in a certain order, and tabulation5 consists of counting the cards or the information on them in certain groups and totalling6 them in these groups. The mechanical tabulation of data is in process of very rapid development and new terms and operations are being introduced almost continuously. Thus mark sensing7 is a process by which pencil marks on a document are automatically translated into punched holes on the same document. This operation has the effect of mechanizing the two manual processes of punching and verification.
- 3. verification n. — verify v. 5. tabulation n. — tabulate v.
The machines used in these operations are the punch1, verifier2, sorter3 and tabulator4. Other machines used in mechanical tabulation are the reproducer5, which copies information from one punched card to another, the interpreter6, which converts the information contained on the cards as punched holes into print on the card, and the collator7, which is used for the comparison or merging of different packs of cards. The summary punch8 is used for preparing cards, sometimes called summary cards9, containing intermediate totals, which can then be used in later tabulations.
Adding machines1 are used for the processes of addition and subtraction, the term calculating machine2 being in general reserved for machines capable of performing also multiplication and division. Small calculating machines and adding machines are often referred to as desk machines3, The multiplier4 is a punched card machine, which performs certain calculations and punches the results on the cards containing the original data. Electronic computing5 makes it possible to perform a large number of calculations within a very short space of time. The machines that do this are electronic computers6.
- 3. nomography n., the part of mathematics dealing with the construction and use of nomograms.
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