Voting to Prioritize?

Things to know before you prioritize backlog/sprint tasks using voting.

Transcript

1. AGILE CARNIVAL 2014 GrayPE Systems (P) Limited Voting to Prioritize? Things to know before you decide!
2. I am @sanjayaksaxena
 cofounder of graype.in
 with @R4CHN4
 (c) GrayPE Systems This is an Intellectual Property of GrayPE Systems Pvt. Limited. No part of this presentation may be used, reproduced, transmitted or translated in any form or by any means, electronic, manual, mechanical, optical or otherwise, without the prior written permission of GrayPE Systems Pvt. Limited. Its unauthorized usage is strictly prohibited. (sanjaya@graype.in) (rachna@graype.in) Pursuing Quantitative Analysis & Decision Sciences (QUADS)
3. 3 When did you use voting to prioritize recently? (c) GrayPE Systems
4. 4 (c) GrayPE Systems
5. 5 Combining individual opinions so as to best reflect the “collective choice of the group” (c) GrayPE Systems
6. Example... 6 There are 3 candidate epics to be Prioritized in an entertainment business: ! (a) Optimal scheduling of shows (Schedule) (b) Self-service ticket printing (Print) (c) Mobile app for bookings (Mobile) ! And there 9 stakeholders… (c) GrayPE Systems
7. 7 You asked every stakeholder to vote for her/his first choice. (c) GrayPE Systems
8. Tally 8 Voters Choice 4 Schedule 3 Mobile 2 Print (c) GrayPE Systems
9. Tally 9 Voters Choice 4 Schedule 3 Mobile 2 Print Schedule has got the highest number of votes. (c) GrayPE Systems
10. Tally 10 Voters Choice 4 Schedule 3 Mobile 2 Print Schedule is the epic of choice! (c) GrayPE Systems
11. 11 This is known as plurality voting method and possibly the most widely used system. (c) GrayPE Systems
12. 12 A Small Problem! Imagine if you knew how each voter ranked every candidate in order of their preference (c) GrayPE Systems
13. Revised Picture 13 Voters Choice 4 1. Schedule 2. Print 3. Mobile 3 1. Mobile 2. Print 3. Schedule 2 1. Print 2. Mobile 3. Schedule (c) GrayPE Systems
14. Voters Choice 4 1. Schedule 2. Print 3. Mobile 3 1. Mobile 2. Print 3. Schedule 2 1. Print 2. Mobile 3. Schedule Revised Picture 14 While Schedule is the first choice of 4 voters ! (c) GrayPE Systems
15. Voters Choice 4 1. Schedule 2. Print 3. Mobile 3 1. Mobile 2. Print 3. Schedule 2 1. Print 2. Mobile 3. Schedule Revised Picture 15 While Schedule is the first choice of 4 voters, It is also the last choice of 5 voters! ! (c) GrayPE Systems
16. Voters Choice 4 1. Schedule 2. Print 3. Mobile 3 1. Mobile 2. Print 3. Schedule 2 1. Print 2. Mobile 3. Schedule Revised Picture 16 While Schedule is the first choice of 4 voters, It is also the last choice of 5 voters! ! Is Schedule the right choice? (c) GrayPE Systems
17. 17 Clearly we need a better method than the plurality voting method. Let’s explore more methods. (c) GrayPE Systems
18. 18 Instant Runoff Voters rank the candidates in order of preference rather than voting for a single candidate. (c) GrayPE Systems
19. Does a candidate have > 50% votes? Eliminate the candidate who received minimum votes Count first preference of every voter Choice finalized! Reorder ranking after elimination ** Tallying Process **Example: If ranking was A - 1, B - 2, and C - 3 then (a) when A is eliminated new ranking becomes B - 1 and C - 2; (b) when B is eliminated ranking becomes A - 1 and C - 2; (c) when C is eliminated, A & B ranking remains unchanged (c) GrayPE Systems
20. Tally 20 Voters Choice 4 1. Schedule 2. Print 3. Mobile 3 1. Mobile 2. Print 3. Schedule 2 1. Print 2. Mobile 3. Schedule (c) GrayPE Systems
21. Voters Choice 4 1. Schedule 2. Print 3. Mobile 3 1. Mobile 2. Print 3. Schedule 2 1. Print 2. Mobile 3. Schedule Tally 21 Schedule is the first choice of 4 voters, but does not have the majority of 5. (c) GrayPE Systems
22. Tally 22 Schedule is the first choice of 4 voters, but does not have the majority of 5. ! Therefore, eliminate Print who has minimum number of votes. Voters Choice 4 1. Schedule 2. Print 3. Mobile 3 1. Mobile 2. Print 3. Schedule 2 1. Print 2. Mobile 3. Schedule (c) GrayPE Systems
23. Tally 23 Reorder ranking now. Voters Choice 4 1. Schedule 2. Print 3. Mobile 3 1. Mobile 2. Print 3. Schedule 2 1. Print 2. Mobile 3. Schedule (c) GrayPE Systems
24. Tally 24 Schedule’s votes remain unchanged; Mobile has now 3 + 2 = 5 votes. Voters Choice 4 1. Schedule 2. Mobile 3 1. Mobile 2. Schedule 2 1. Mobile 2. Schedule (c) GrayPE Systems
25. Tally 25 Schedule’s votes remain unchanged; Mobile has now 3 + 2 = 5 votes. ! Mobile is declared the choice epic! Voters Choice 4 1. Schedule 2. Mobile 3 1. Mobile 2. Schedule 2 1. Mobile 2. Schedule (c) GrayPE Systems
26. 26 Some Trivia! Did you know Instant Runoff is used at ! All major categories at The Oscars & Presidential Election in India Source: http://en.wikipedia.org/wiki/Academy_Award http://en.wikipedia.org/wiki/Instant-runoff_voting (c) GrayPE Systems
27. 27 Approval Voting Each voter can approve of (i.e. vote for) up to (N - 1) candidates, where N is number of candidates; candidate with most votes becomes the final choice. ! This is also known as Multi Voting. (c) GrayPE Systems
28. Recall the Revised Picture 28 Voters Choice 4 1. Schedule 2. Print 3. Mobile 3 1. Mobile 2. Print 3. Schedule 2 1. Print 2. Mobile 3. Schedule (c) GrayPE Systems
29. Recall the Revised Picture 29 Since voters can vote for 2 candidates, they would have voted for their first two choices. (c) GrayPE Systems Voters Choice 4 1. Schedule 2. Print 3. Mobile 3 1. Mobile 2. Print 3. Schedule 2 1. Print 2. Mobile 3. Schedule
30. Voters Choice 4 1. Schedule 2. Print 3. Mobile 3 1. Mobile 2. Print 3. Schedule 2 1. Print 2. Mobile 3. Schedule Yet another Tally! 30 (c) GrayPE Systems
31. Yet another Tally! 31 Print receives (4 + 3 + 2) = 9 votes, whereas Mobile and Schedule receive 5 and 4 votes respectively. ! Voters Choice 4 1. Schedule 2. Print 3. Mobile 3 1. Mobile 2. Print 3. Schedule 2 1. Print 2. Mobile 3. Schedule (c) GrayPE Systems
32. Yet another Tally! 32 Print receives (4 + 3 + 2) = 9 votes, whereas Mobile and Schedule receive 5 and 4 votes respectively. ! Print is declared as the final choice! Voters Choice 4 1. Schedule 2. Print 3. Mobile 3 1. Mobile 2. Print 3. Schedule 2 1. Print 2. Mobile 3. Schedule (c) GrayPE Systems
33. 33 More Trivia! Did you know if Approval Voting was used in year 2000 US Presidential Elections, Al Gore would have won instead of Bush! Source: http://www.psmag.com/navigation/politics-and-law/brams-use-approval-voting-in-presidential-primaries-38613/ (c) GrayPE Systems
34. Journey so far 34 3 epics (c) GrayPE Systems
35. Journey so far 35 3 epics 9 stakeholders (c) GrayPE Systems
36. Journey so far 36 3 epics 9 stakeholders 3 methods (c) GrayPE Systems
37. Journey so far 37 3 epics 9 stakeholders 3 methods 3 different outcomes!? (c) GrayPE Systems
38. 38 What determines the “collective choice”? ! Voters ! or ! Voting Method (c) GrayPE Systems
39. 39 With no change in voters’ choice, change in voting method may change the outcome! (c) GrayPE Systems
40. 40 It’s time to revisit the “Revised Picture” again (c) GrayPE Systems
41. Revised Picture Again 41 Voters Choice 4 1. Schedule 2. Print 3. Mobile 3 1. Mobile 2. Print 3. Schedule 2 1. Print 2. Mobile 3. Schedule (c) GrayPE Systems
42. Revised Picture Again 42 Reorganize this matrix to gain a deeper insight; where rows define the ranks, columns define the candidates, and each cell (i, j) indicates the number of Voters - who ranked jth candidate at ith place. Voters Choice 4 1. Schedule 2. Print 3. Mobile 3 1. Mobile 2. Print 3. Schedule 2 1. Print 2. Mobile 3. Schedule (c) GrayPE Systems
43. Revised Picture - Another View 43 Schedule Print Mobile 1st Choice 4 2 3 2nd Choice 7 2 3rd Choice 5 4 You can easily visualize - how with no change in choice, outcome has changed when a different voting method is used. (c) GrayPE Systems
44. 44 With this view in background, let’s look at one more voting method before we conclude. (c) GrayPE Systems
45. 45 Borda Count Voters rank the candidates in order of preference rather than voting for a single candidate. French mathematician and physicist Jean-Charles de Borda devised this system in 1770. Read about him at http://en.wikipedia.org/wiki/Jean-Charles_de_Borda (c) GrayPE Systems
46. Tallying Process 1. Assign 0 points to every candidate; 2. Add (N - j) points to a voter’s jth rank candidate; 3. Repeat step 2 for every voter and rank; 4. Candidate with highest number of points is the final choice. (c) GrayPE Systems
47. Tally 47 Schedule Print Mobile 1st Choice 4x2=8 2x2=4 3x2=6 2nd Choice 7x1=7 2x1=2 3rd Choice 5x0=0 4x0=0 Total 8 11 8 Print is declared as the epic of choice! (c) GrayPE Systems
48. 48 Some Facts ‣ There are many more voting methods ! ‣ Different Voting Method may produce different outcome with the same voters’ choice ! ‣ Mathematics of voting is a complex subject ! ‣ Choice of the voting method depends on the context (c) GrayPE Systems
49. 49 Deciding which method to use Context Method Select 1 out of 2 choices Plurality Shortlist few from a list Multi Voting Select 1 out of >2 choices Borda Count Disclaimer: Mathematics of voting is a complex subject. There may not exist a perfect method for a given context. Use your discretion before adopting a voting method. (c) GrayPE Systems
50. 50 Now you know! ! Go-ahead and prioritize! ! (c) GrayPE Systems
51. 51 Thank you! Resources & References: [1] Chaotic Elecetions - A Mathematician Looks at Voting by Donald G. Saari [2] Voting Methods at http://plato.stanford.edu/entries/voting-methods/ [3] Voting Research - Voting Theory at http://www.princeton.edu/~cuff/voting/theory.html (c) GrayPE Systems