A suitably large sample size is needed, but after a certain amount of samples, any added one will not provide much more security about the statistic. I think usually to be considered empirically important you try to get 100-300 samples. The rule of thumb for accuracy of a given statistic is 1/n, where n is the amount of samples.
A suitably large sample size is needed, but after a certain amount of samples, any added one will not provide much more security about the statistic. I think usually to be considered empirically important you try to get 100-300 samples. The rule of thumb for accuracy of a given statistic is 1/n, where n is the amount of samples.