Testimonials

Thank you for offering the random number generator. I have used it for a research on the effects of target specific communications in a N=2000 population of Dutch War Veterans. In the experimental setting it was necessary to randomise the research population and to divide them over four sub-groups, similar in size. The only acceptable way was to do so by adding a randomised variable in SPSS. Afterwards it was possible to assign the subjects to one of the groups by sorting on the randomized variable. Of course I gave due credit in the report by mentioning your service and revealing the URL.

—drs. Rudy C. de Jong, Dronten Professional Agricultural University, The Netherlands

I study the life-cycle of viruses, and I perform lots of tissue culture experiments. In order to try to develop theories to explain some results I was getting, I wrote a computer program that uses a Monte Carlo scheme to simulate infection of cells by viruses. I need a different random number for each simulated virus, in order to randomly assign it to a cell that it ‘infects.’ In order for the results to be meaningful, I need to simulate tens of thousands of ‘cells’ and hundreds of thousands of ‘viruses,’ so I need hundreds of thousands of random numbers. The pseudo-random numbers produced by the Apple Macintosh built-in linear congruental generator proved themselves to be not good enough for the job, as I found that some numbers were chosen too often, a definite no-no for my purposes. Then I saw the NY Times article about this site and gave it a try. First I tried using Random.org numbers to seed the Macintosh generator at frequent intervals during the execution of the simulation, but it did not solve the problem. So I tested using all numbers from this site and they passed my quality test. So now I download several batches at a time of 10,000 numbers between 1 and 40,000 and string them into big files as the sources of my numbers. I'd like to be able to download them in even bigger batches, though. Thanks for a truly useful service!

—David N. Levy, University of Alabama at Birmingham