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Exercise 15a — a Yes/No profile (which method is this?)

Generated from ex15_approval_yes_no.yaml — do not edit by hand. Regenerate: python STARVote_LH_tabulation_engine/tools_adam/scripts/build_yaml_pages.py.

Method: Approval Voting · 1 seat · Expected winner: Blair

▶ Live on BetterVoting: vote · results ↗ (election d4v2dh · test BV2258).

Scenario

Part (a) of Exercise 15 — "Read the ballot, name the method."

35 voters, three candidates, and a ballot that records only Yes or No per candidate — no ranking, no scores, and voters approve different NUMBERS of candidates. That combination identifies the method: this is APPROVAL VOTING. Blair wins with 28 approvals of 35 ballots (80%), ahead of Cosmo 22 and Ada 15.

Note the shares add to well over 100% — approval percentages are shares of BALLOTS, not of a divided pie, and that is the tell most readers miss.

A textbook-style prompt (a Yes/No table with weighted voter blocs), rebuilt here with named candidates so the columns line up A/B/C -> Ada/Blair/Cosmo. Companion file ex15_approval_pairwise.yaml re-reads these same ballots pairwise; part (b) is ex15_score_profile.yaml.

Exercise page: ../ex15_read_the_ballot.md Live results: https://bettervoting.com/d4v2dh/results (BV2258, race 1 of 2 — BetterVoting's own Approval count agrees: Blair.)

Ballots

Row 1 = candidate names; each later row is one voter's approvals (1 = approve, 0/blank = not approved).

Count:Ada,Blair,Cosmo
15:0,1,1
8:1,1,0
7:1,0,1
5:0,1,0

What the engine says

Full report from the _tabulated mirror (regenerated on every run; every analysis forced on):

--- Approval Voting (single winner) ---
 Tabulating 35 ballots (any non-zero score = approval).

Ballots:
   columns = Ada, Blair, Cosmo      (1 = approve; 0 = not approved)
    15 × 0,1,1
     8 × 1,1,0
     7 × 1,0,1
     5 × 0,1,0

   Blair -- 28 (80%) -- Elected
   Cosmo -- 22 (63%)
   Ada   -- 15 (43%)

[Approval Distribution] (how many candidates each ballot approved)
   65 approvals across 35 ballots — average 1.9 of 3 (range 1–2).
     approved 1: 5 ballots
     approved 2: 30 ballots

[Co-Approval Matrix]
 Of the voters who approved the ROW candidate, the % who ALSO approved the COLUMN candidate.
          | Blair  | Cosmo  |  Ada   |
   -----------------------------------
   Blair  |   --   |  54%   |  29%   |
   Cosmo  |  68%   |   --   |  32%   |
   Ada    |  53%   |  47%   |   --   |

Winner — Approval Voting (single winner)
  Blair

Run it yourself:

python STARVote_LH_tabulation_engine/starvote_larry_hastings.py 01_STAR/05_Practice/cases/ex15_approval_yes_no.yaml

See also

More cases in this set: ex01_district_combined · ex01_district_east · ex01_district_west · ex02_bella_exits · ex02_nine_ballots · ex02_tenth_ballot · ex03_five_verdicts · ex04_olympics_1994 · ex05_center_squeeze · ex06_bullet_backfire · ex06_bullet_honest · ex07_vanishing_votes · ex08_minimal_reversal_2c · ex08_minimal_reversal_3c · ex09_game_night_cycle · ex10_generous · ex10_reticent · ex11_spoiler_added · ex11_two_way_base · ex12_bloc_sweep · ex12_proportional_share · ex13_approve3 · ex13_approve4 · ex13_bullet · ex13_opinions · ex14_two_novels · ex14_two_novels_fullranks · ex15_approval_pairwise · ex15_score_profile