Measuring a Small Number of Samples, and the 3v Fallacy: Shedding Light on Confidence and Error Intervals

Many solid-state circuits papers today report the mean and the standard deviation of measurement results obtained from a small number of test chips and then compare them with numbers other authors obtained. Almost none of them discuss confidence intervals, ranges of values for that standard deviation within which the true value lies with a certain probability. Many implicitly assume that the range would contain all but 0.27% of chip samples to be expected in volume production. This is incorrect even if it is certain that the measured quantity is exactly normal distributed.