Explicit approval voting

Wikimedia and Wikipedia elections are held using a rated voting system in which voters must choose Support, Oppose, or Neutral, for every candidate. The winner is the candidate with the highest support percentage: the highest proportion of Support votes out of combined Support and Oppose votes = $S \over S+O$.

This is mathematically equivalent to 2-level Score voting with averaging, though the abstain votes are explicit rather than implicit, and the levels are essentially (−1, +1) rather than (0, 1), so they are affected by the psychological consequences of disapproval voting.

The Wikimedia Foundation has used this method for Board of Trustees and Funds Dissemination Committee elections in 2013, 2015, and 2017, after previously using Approval voting and Schulze method. Wikipedia uses this in a non-binding way for Administrator nominations, etc.

If tallied using normal Score voting rules (where O=0, N=1, S=2), the 2015 Board election would have had different winners, with the candidate in 4th place moving up to 2nd. The 2017 Board and 2015 FDC elections would have had a different top-3 order, but the same 3 candidate would have won.

In all 8 elections from 2013-2017, the most common vote was Neutral, which was cast about twice as often as Support, which in turn was cast about twice as often as Oppose.