When using iNaturalist, one of the things that encourages me to continue photographing new taxa is the idea of making some kind of “important” observation for science. Obviously every observation is important on some level, but I’m more talking about the observations of uncommon taxa or taxa outside their usual range. I think this is something that can be said for a lot of people, while not everyone is looking to find something super noteworthy, if someone knows they made such an observation it makes them feel good and creates a nice positive feedback loop to further encourage people to seek out new observations. If people are given some kind of feedback that their observations are important, it encourages them to do more.
There are two easy ways I could see an observation as being regarded as more “important”: rare (or at the very least undersampled) species and species with represent range expansions of the present distribution of observations. A feature to order specimens by greatest to least number of total observations has already been discussed, but I can’t find any discussion of the latter.
By this I mean things like filling in observations of taxa at the marginal edges of their native range or filling in gaps (mostly between urban centers) where a species probably occurs but hasn’t been sampled yet. This feature could be relatively easily implemented by calculating the minimum distance to the nearest observation of the same taxon by latitude/longitude coordinates and then sorting observations within one’s account based on that.
This wouldn’t be the most useful from a purely scientific perspective, but as mentioned above individuals getting direct positive feedback that logging their observations means something would encourage them to log more observations (which benefits everyone). This would also encourage users to make observations in areas to “fill in” gaps in the native range of species where they probably occur but just haven’t been sampled yet. This could also be very useful from the developer/scientist end of things to highlight observations that might be misidentified far out of their native range or helping to define the borders of a naturally occurring range.