Thanks everyone for the feedback.
Branch Disagreements
Regarding ‘branch disagreements’, upupa-epops’s use case Let’s say someone posted a very blurry picture of a ladybug... is the one we had in mind. While we agree it should be rare and backed up by the community and comments, the idea is that there should be some mechanism for the community to role back the taxon that an observation is ‘filed under’ if the observer is not responsive and if the community consensus is that while it could be Seven-spotted Ladybug its really impossible to tell and we should err on the side of caution.
Regarding @Pisum and other’s concern that we’re lowering the bar with branch disagreements, eg: note that with the proposed new prompt, you’ll no longer need to know that there’s no way anyone could confirm / deny, you’ll just need to think that there’s no way anyone could confirm or deny. that’s a slightly lower bar for disagreement. those who ignored the letter of the current prompt to disagree would now have the new prompt wording on their side. the idea was actually to raise the bar (ie make it rarer for people to ‘branch disagree’). The concern with the existing ‘evidence’ based language is that if @charlie observed a plant and ID’d it to species because he’s an ‘expert’ but his photo didn’t capture all the characters necessary to identify it to species, someone else shouldn’t roll it back to genus merely because the ‘evidence was not sufficient’. The ‘I don’t think we can be certain…’ language was meant to capture the spirit that the community doesn’t think anyone is intentionally/knowingly advocating for that species which would eliminate the charlie situation (we can be reasonably certain charlie knows what he’s doing) but would cover for example, someone blindly clicking on a computer vision suggestion (in most of these cases the community can ascertain that the precision associated with such an ID wasn’t intentional).
Again, the idea is that the ‘branch disagreement’ lever should be very rarely pulled, so we agree with concerns about this lever being over-used. But we think the use case articulated by upupa-epops is legitimate, especially if the identification in question makes the observation sufficiently unusual/unlikely that it decreases the credibility of the site (even though it ‘could’ be that taxon) and the observer is unresponsive. But if folks think this is too niche a use case for a tool that could be broadly misused, thats fair.
Leading Disagreements:
Regarding ‘leading disagreements’, @Pisum and @tchakamaura brought up a legitimate issue with our plans we didn’t think about. First some terminology. In the following example User B’s ‘Identification taxon’ is Epilachna borealis.
Because the Identification Taxon is a sibling to and not an ancestor of the Community Taxon (C. septempuctata), its very easy to recognize the not only the ancestry to the Identification Taxon (green) which User B is certain the observation is, but also ‘Disagreement Branch’ (orange) which User B is certain the Taxon isn’t. It extends from the Community Taxon back to the common ancestor with User B’s Identification Taxon.
But in the case of ‘ancestor disagreements’, e.g.
Psium’s is correct that sometimes we might want to set the Identification Taxon in one place (e.g. ‘I’m certain this is Family Coccinellidae’) but the root of the disagreement branch somewhere else (e.g. ‘I’m certain this is not in the genus Coccinella, but it could be some other genus in the tribe…’)
Psium is correct that under the planned changes, this can’t be articulated. Choosing ‘Leading Disagreement’ will set the Identification Taxon at Family Coccinellidae but set the ‘disagreement branch’ at C. septempuctata which isn’t whats intended.
Similarly, choosing ‘Branch Disagreement’ (which isn’t the could-be-but-can’t-be-certain use case we’re intending by that choice) also wouldn’t do what’s intended as it would define the disagreement branch as everything below the Identification Taxon
Wrapped up in this is that since identifiers can only trigger disagreements by suggesting a taxon that is an ancestor of the Community Taxon (not the Observation Taxon), if User B did a ‘leading disagreement’ the Community Taxon would be at Family Coccinellidae but the Observation Taxon would be at Genus Coccinella and there’d be no way for future identifiers to trigger a disagreement with Genus Coccinella.
Do we need functionality that allows the flexibility for an identifier to:
a) disagree with taxa other than the Community Taxon
b) explicitly choose not just their Identification Taxon but also the root of the Disagreement Branch?