ultimately, the gameplay goal would be to try to guess a location, but you could add an extra challenge by presenting only images of the species in the place without providing names of the species. (that extra challenge should probably be optional though.)
i don’t think you want to get into this kind of logic. it’s possible of course that different places will have similar taxa, but given enough taxa, each place should end up with a relatively unique “fingerprint”.
i think the way i would do it, the game simply picks a place and then presents 5-10 of the most popular taxa from each of these categories:
- vertebrates (last 30 days)
- invertebrates (last 30 days)
- plants and other organisms (last 30 days)
- vertebrates (last year)
- invertebrates (last year)
- plants and other organisms (last year)
you could click on any of the taxa from any category, and that would present you a random observation of that taxon from the appropriate taxon + time category (last 30 days or last year).
then the player has to select a county-equivalent place on a map.
the game shows the popular taxa for the player’s selected place for comparison, and calculates the distance between the centroid of the player’s guessed place and the centroid of the place picked by the game. the lower difference, the better.
you would probably want to stick with RG observations, and there will be no way to guarantee that any observation is identified correctly, though you could do additional things like looking for the observations with the most favorites or most IDs without disagreements to hopefully increase the quality of the observations that are shown.
not sure why this makes a difference.