Last Uncertainty Wednesday, I used meteorite impact data to make the point that sample variance may be much smaller than actual variance. Following the post, I was asked a great question on Twitter: “Is there such thing as estimation error on sample variance?” The answer is yes. Just as we saw earlier that the sample mean has a distribution, so does the sample variance. If you have different samples, you will get different variances and those will form a distribution. We are thus faced with e...