1300 is a nice sample size if you're sampling randomly. If 1/3 of people have a trait, you'll get a good sense it's common after asking 300 people, even if the

1300 is a nice sample size if you're sampling randomly. If 1/3 of people have a trait, you'll get a good sense it's common after asking 300 people, even if the total population is a million. Surveying more gives diminishing returns as the result quickly converges on the real proportion. The real problem with all surveys is the sampling isn't truly random, which skews results.