A naive approach [16, 17] is to regard the different method results for the same analyte as being repeated estimates of a single true mean, and to compute the consensus mean as the unweighted mean of the different group means, and the consensus uncertainty as:
|
(2) |
where n is the number of groups, the ordinary sample standard deviation s is computed on the mean values themselves, and t' is the appropriate tabulated value of the Student t percent point function for achieving 95% confidence. A very high t value for the case n = 2 (t ≈ 13) typically precludes using this approach when only two groups are available. Otherwise, this method is useful in that it is simple, probably something that many practitioners would attempt to use, and will often give a consensus value identical or very close to other naturally weighted methods. The naive method yields a less conservative uncertainty than those provided by other methods which take other sources of error into account, but it can serve as a baseline for those methods.