To put this in perspective, a sample size of 3000 even randomized is relatively meaningless
That defeats the entire point of surveys. Do you understand what surveys are?
The sample size was almost 3,000, and it was random. How many more will satisfy you? 4000? 5000?
Hundreds of thousands of respondents is unlikely, and given timeframes, by the time the firm gathers the information the survey would have been rendered moot.
ex pede herculem. From the sample we judge (or better put, estimate) the whole.
The key is a decent sample size of *representative samples.*
Given the nature of the survey and how it was accessed, PriceGrabbers got the second part right.
Given that, generally, samples of 1,000 are well regarded for national surveys, they also got the first part right.
http://www.dfrank.com/accuracy.htm
With a sample of 100 the 90% level of confidence of any observed percentage is within +/- 8.2%. As the sample increases, the precision increases and the range of error gets smaller.
Thus, when we measure a 49% approval rate, say, with a sample of 1,000 people we can be 90% sure if we do the survey again, the results will be within 2.6 points of the 49%, or between 46.4% and 51.6%. We improve our precision quite a bit by going from 1,000 to 2,000 sample size (0.8 points), but only marginally by going from 2,000 to 3,000 (0.3 points). The selection of sample size should depend upon the consequences of coming to a wrong conclusion, and the cost of adding sample size.
Surveys are at best, indicators. Which is exactly what they are meant to be, and this particular one is no different.
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