1. Plurality with Elimination
Voting Methods
Plurality with Elimination

2. Plurality with Elimination
T. Serino
Method:
1. Use the plurality method to rank the candidates.
2. The last place candidate is eliminated in each round. Adjust ballots for another round of voting (if necessary).
3. Repeat steps one and two until the winner has a majority of votes.

3. Plurality with Elimination
T. Serino
“majority of votes”
means more than half of all the votes.
Note:
*If there is a tie for last place in any round, the
candidates that are tied are both eliminated.
*If the winner has a majority vote in any round,
he/she can be determined as the winner
Immediately (without more rounds of voting).

4. Plurality with Elimination
T. Serino
Remember the election between these three candidates?
Amy: votes
Beatrice: votes
Carl: votes
Amy and Beatrice are tied for last in the first round of voting. This means that they are both eliminated.
Using Plurality with Elimination method: Carl wins!

5. Plurality with Elimination
T. Serino
Remember the Mathematics Anxiety Club? The preference table for their election is shown below.
A = 14
B = 4
C = 11
D = 8
Tally the number of first place votes for each candidate.
B is eliminated in round 1

6. Plurality with Elimination
T. Serino
Adjust the ballots
With candidate B eliminated, our new ballot looks like this.
1st A C D D C
2nd C D C C D
3rd D A A A A

7. Add Title Here Round 2 A – 14 C – 11 D – 12 C is eliminated
T. Serino
Round 2
A – 14
C – 11
D – 12
1st A C D D C
2nd C D C C D
3rd D A A A A
C is
eliminated
1st A D D D D
2nd D A A A A

8. Plurality with Elimination
T. Serino
Round 3
A – 14
D – 23
1st A D D D D
2nd D A A A A
D wins!

9. Try this.
T. Serino
Use the Plurality with Elimination method to determine the winner of this election.
1st B C A D A A
2nd D B D B D C
3rd C D B C B B
4th E E E E C D
5th A A C A E E
How many rounds of voting did it take to determine a winner?

10. athematical M D
ecision
aking