Summability criterion: Difference between revisions
→Examples
No edit summary |
|||
Line 53:
====== Median methods ======
Alternatively, precincts may sum up the number of times each candidate was ranked at each of the <math>c</math> possible ranks (or grades). This ''positional matrix'' can then be used to compute the result for any weighted positional method after the fact, or for median-based methods like [[:Category:Graded Bucklin methods|Category:Graded Bucklin methods]]. This shows a contrast between median methods and point-scoring methods, where the grade level doesn't matter, only the strength/quality/degree of the grade (i.e. in
===== Cardinal methods =====
Line 102:
|}
If some other voter ranked B above A, then that would be added into this matrix by adding a 1 to the B>A cell (i.e. increasing it from 0 to 1), etc.
=== Non-summable methods ===
Line 111 ⟶ 107:
===== Instant-runoff voting =====
[[IRV]] does not comply with the summability criterion. In the IRV system, a count can be maintained of identical votes, but votes do not correspond to a summable array. The total possible number of unique votes grows factorially with the number of candidates.
== Importance of summability ==
| |||