While emotionally I share Biker's opinion that "XP should be earned by writing good nodes and by reading and voting on good nodes", this can weaken PM I think in the following ways.

- Constructive feedback is educational regardless of whether it is -- or ++. While I personally hardly ever cast -- votes, by introducing another thing to think about when voting, your suggestion will likely have a slight chilling effect (reducing both ++ and -- votes) which will reduce the total quantity of community interaction. Not sure if total quality will suffer..

- Many potentially valuable analyses of community interaction such as those based on patterns of ++/-- voting in threads which I suggested at the end of a recent thread will be weighted by implementation of your suggestion. If we understand what is going on we can maybe compensate for it with empirical calibration though.

- Implementation of "no XP++ on casting -- vote" means something else (maybe from my list?) will not be implemented. I don't think your suggestion is as pressing as some other possibly empowering functions.

- In general we only have one binary bit of information (--/++) of possible feedback which isn't a whole lot. I think we need much more, and those additional categories should be editable by the community possibly. Considering the endless discussions about the ramifications of that one bit, it seems that feedback is important and maybe we are unsuccessfully cramming a lot of signification into the one bit. So I'd be against reducing the value of the only votable information bit we have by reducing the distinction between its values and the popularity of voting. Of course your suggestion would be immensely useful if we added a participation score and a contribution score, and made XP a calculation based on the two (or scrapped XP altogether).

- Consideration of a system which includes elements of the previous point and your own suggestion, sounds like maybe we should remove the ability to make -- votes and instead introduce at least one pulldown menu of which each option results in XP or some other dimension being incremented by one. This could also be done with radio buttons.

So I identify with your suggestion emotionally Biker but think it should not be implemented immediately, nor without simultaneously making other changes to the voting page and XP system, at the risk of having an overall negative effect on PM community interaction. I think we would have a much more positive effect by raising the entire community's interaction to a higher, more complex level (like solving an economic problem with growth) that provides more dimensions of feedback, discourse, and education.