I like the "perceived distinction" of the various scoring methods:
- Upvote – directly boost the ranking of an answer you like
- Downvote – directly lower the ranking of an answer you dislike
- Thank – send appreciation to the answerer, possibly secretly boost their reputation/authority somehow
- Not Helpful – select a reason for flagging the answer, possibly replacing or adding additional explanation for your dissatisfaction… Possibly secretly lower answerer's reputation/authority somehow, or start to flag them to admins for review after multiple Not helpfuls within a given time period/category/etc… (conjecture! but would be a cool way to handle the 'bad answer vs. bad answerer' issue).
- Comment – Another way to chime in, positively or negatively. Another potential source for scoring reputation – more comments either way could indicate the "excitement level" of an answer. Or its lack of clarity. Or any number of other things. Note that "Not Helpfuls" are included as comments – certainly a negative factor.
(Note: All of the above is simply my perception of how the system may use differentiation to help auto-moderate answers in the most efficient manner possible – there may be truth to any, all, or none of the above)
Currently the issue I have with the system is the apparent inability to both upvote AND mark an answer as "Not Helpful" – in practical terms, this comes up fairly regularly – sometimes even unhelpful answers do more to spark further discussion/resolution of an issue than the one-liner answers that are completely on-topic.