Using citation analysis, sets of documents can be compared as independent
samples; for example, in terms of average citation counts using potentially
different reference sets. From this perspective, the size of samples matters
only for the identification of significant differences and estimating margins
of error. Using the percentile rank approach, differences among citation
distributions can be studied non-parametrically and in a single scheme.
Comparison among the sets clarifies that the different sizes of samples affect
the weighing of the probabilities and therefore the rankings.