The first attempt to provide researchers with a ready supply of random digits was in 1927, when the Cambridge University Press published a table of 41, 600 digits developed by L . H . C . Tippett.
42.
John von Neumann cautioned about the misinterpretation of a PRNG as a truly random generator, and joked that " Anyone who considers arithmetical methods of producing random digits is, of course, in a state of sin ."
43.
In recent decades, this has been accomplished by " random digit dialing, " in which a computer selects area codes and exchanges and then makes up the last four digits at random to form complete telephone numbers.
44.
The results of a long run from the RAND machine, filtered and tested, were converted into a table, which was published in 1955 in the book " A Million Random Digits with 100, 000 Normal Deviates ".
45.
In the mid-1940s, the RAND Corporation set about to develop a large table of random numbers for use with the Monte Carlo method, and using a hardware random number generator produced " A Million Random Digits with 100, 000 Normal Deviates ".
46.
On 29 April 1947, RAND Corporation began generating random digits with an " electronic roulette wheel ", consisting of a random frequency pulse source of about 100, 000 pulses per second gated once per second with a constant frequency pulse and fed into a five-bit binary counter.
47.
This decay is random, as guaranteed by laws of quantum mechanics, so by training a Geiger counter on a sample of krypton 85 and feeding the signal to a computer, Hotbits ( www . fourmilab . ch / hotbits ) generates a constant stream of random digits.
48.
But, in a stunning demonstration of the power of sheer practice to break barriers in the mind's ability to handle information, Ericsson and associates at Carnegie-Mellon University have taught college students to listen to a list of as many as 102 random digits and then recite it correctly.
49.
The firm has introduced many research products, including Random Digit Dial telephone samples with known business numbers removed ( called Super Samples ); a sample screening service which removes most non-working telephone numbers; " LITe " ( low incidence targeted ) samples; and the SSI-SNAP online ordering system.
50.
He remained with the company after the sale, but in 1977 left to start a new company, Three Sigma Research, in Larchmont, N . Y . After a few years in business, he sold the new company, which did important early work in random digit dialing, another marketing research technique, to Simmons Market Research.
