The first step in using DNA is to generate a temporary list of random phone numbers for the system to dial.
There is no real limit to how many temporary random numbers you may have in the system. Realistically, you could literally have millions of randomly generated phone numbers in this temporary file.
So, unlike generating random numbers that are immediately added to your respondent file (when you use Pure Random within ComQuest), when you use DNA, you could actually generate 50,000 or 100,000 phone numbers to later be verified (in multiple verification sessions). For example, say you generate 100,000 random phone numbers. These numbers remain available for verification until they are either all dialed, or you empty the temporary Random file. As the verification program, (running on 4 Fileserver phone lines) can only dial and verify 1,000 to 1,200 phone numbers per hour, it would then take you almost 100 hours of dialing before the 100,000 random numbers were depleted.
If you're sure you're not going to be changing your list of Area Code and Prefixes anytime soon, you might as well generate a large quantity of temporary random numbers all at once, rather than have to keep generating smaller quantities of random numbers on a more frequent basis.
When generating random phone numbers, the Area Code and Prefix combinations you have entered into ComQuest are used; (see Changing Prefixes).
These are the same Area Code and Prefix combinations that are also used when you use Random Number Generation (except the random numbers generated by that procedure actually get added to the respondents file). To view, add, change or delete any of the Area Code and Prefix combinations, simply go to Data Management / New Phone Numbers / Random Numbers / Change Prefixes on the ComQuest menu.
On the Generate Random Numbers screen, simply use the spin box to indicate how many random numbers you wish to generate (or type in the exact number you want - up to 200,000). Depending on the speed of your computer, how much memory you have, and how many respondent records and random numbers you already have in the system, your Fileserver should be able to generate between 1,000 to 10,000 random numbers per minute.
Here is the process by which random numbers are generated:
|•||One of the Area Code and Prefix combinations you have stored in the system is selected at random.|
|•||A random 4-digit number (between 0000 and 9999) is generated and appended to this Area Code and Prefix combination.|
|•||Your respondent file, as well as the temporary random number database, are both checked for this resultant 10-digit number. If the number exists in either file, it is not added or saved, and the process begins all over (by selecting a new random Area Code and Prefix combination).|
Whenever you have more than a thousand or so numbers in the temporary random file, you can move to the next step, which is to verify the status of random numbers.
To determine how many remaining (uncalled) random phone numbers you have in your temporary database, either go into Purge Random Numbers or Verify Numbers and then exit out.