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Accracy of a survey
Message posted by david on February 13, 2001 at 12:00 AM (ET)
How can I determine the accuracy of a surevy? For example a sample size of 200. And what exactly does this say about the surevy?
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Re: Accracy of a survey
Message posted by Darius on February 13, 2001 at 12:00 AM (ET)
The accuracy of the survey is the margin of error at a specific confidence level (90,95,99% etc.).
For a discrete variable 0/1 or yes/no:d= Z * sqrt(P*(1-P)/n)
being
Z=1.65,1.96, 2.58 for 90,95 and 99% conficence levels respectively.
P= the proportion of the population that agree
n= the sample size
d= the margin of error
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