I am found of stats and figures. Dealing with umbrella-projects with hundreds of involved people, I came across situation, when basic stats do not reflect clearly the depth of the project and its community. In many cases, high number of observations is a result of a single person efforts, whereas large number of observers do not necessarily leads to big bang of data.
In science, the h-index (https://en.wikipedia.org/wiki/H-index) is widely used to evaluate global contribution of a scientist (or of a group). The index is based on the set of the scientist’s most cited papers and the number of citations that they have received in other publications. For the iNat collection and umbrella projects, h-index could be the function of a descending list of top-observers based on the number of observations or (and) species.
For instance, in https://www.inaturalist.org/projects/caterpillars-of-eastern-north-america h-index is 86 (for observations) and 45 (for species).
In https://www.inaturalist.org/projects/flora-of-russia umbrella, overall h-index is 150 (for observations) and 133 (for species). Within this project, the highest h-index (for observations) got regional collection project https://www.inaturalist.org/projects/moscow-oblast-flora (43), which is not a leader either in species, observers or observations. The index shows adequately the most active general community of observers not influenced by the activity of leaders or a heap of dormant accounts.
It is also possible to use h-index for observers based on personal species list sorted in descendent order by the number of observations.