"Mark all observations as seen" or "Mark all observations as viewed"?

[damianooldoni]

Citing @timadriaens from https://github.com/riparias/early-alert-webapp/issues/227#issuecomment-1525717178:

"Mark all observations as seen" sounds quite odd in English (also observed and seen is kinda the same), more correct would be "Mark all as viewed".

I add a screenshot to give some context about this EN related question:

I think the opinion of some EN native speaker is important now as we had this discussion with some other colleagues as well and I am not the right person to decide it.

[timadriaens]

there is just something very strange about the expression "unseen observation". If you observed, you saw something. I'll ask some native speakers if they can think of a better alternative.

[damianooldoni]

Yes, @timadriaens, please ask. Meanwhile, I copy paste the meaning of Erin Roger from Australia (Atlas of Living Australia):

I think it should be seen and unseen (but I can’t really explain why). Either way keep it consistent between them. I don’t think people say un-viewed which is why I’d choose unseen.