```Date: Mon, 8 Dec 2008 17:20:57 -0500 Reply-To: Gene Maguin Sender: "SPSSX(r) Discussion" From: Gene Maguin Subject: Re: mail quantities determination Comments: To: RAbraham@aaalife.com In-Reply-To: Content-Type: text/plain; charset="us-ascii" Renji, Yes, that's pretty much what I figured. Here is how I'm thinking of this problem right now. Suppose your expected (i.e., predicted) response rate is 2%. Then the variance is .98*.02 = .0196 and the sampling variance, assuming a sample of 10,000, is .0196/10000 = 1.96E-06 and the standard error is .00138. If you take a 1SD confidence interval your response rate would be .01862 to .02138, or 1862 to 2138 persons. Gene Maguin >>Let me try to explain it once more. We have a model which is used for scoring and selecting records for mailing campaign. From the response rates obtained from past mailing campaigns and several other factors, we normally calculate the quantity to be mailed from the population. For example, Population - 1 mil Mail Quantity - 500K After scoring the population with the model, the records are ranked from 1 -10 based on the scores (records with highest scores as 1, and records with lowest scores as 10). To meet our required mail quantity of 500K, we would have to select records from Decile 1-5. But since we also want to find out how the model performs (in terms of response rates) in the bottom deciles (i.e. deciles 6-10), we want to mail small samples that fall in the deciles 6-10. So we select 10K records from each of the bottom deciles (6-10). The 10K quantity from each decile is not calculated using any scientific method. What I would like to know is if there is any scientific method to determine the additional quantities for just the bottom deciles. ===================== To manage your subscription to SPSSX-L, send a message to LISTSERV@LISTSERV.UGA.EDU (not to SPSSX-L), with no body text except the command. To leave the list, send the command SIGNOFF SPSSX-L For a list of commands to manage subscriptions, send the command INFO REFCARD ```

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