A Pairwise Comparison is the process of comparing candidates in pairs to judge which of each candidate is preferred overall. Each candidate is matched head-to-head (one-on-one) with each of the other candidates. Each candidate gets 1 point for a one-on-one win and half a point for a tie. The candidate with the most total points is the winner. The comparison is sometimes represented by the development of a Pairwise Matrix.
Definition: Pairwise comparison is a method of comparing entities in pairs to judge which one is preferred.
When is a Pairwise Comparison Used
A Pairwise Comparison is mostly used in scientific studies, voting systems, social choice, public choice, and requirements engineering.
Conducting a Pairwise Comparison
Below is an example of the process of developing a Pairwise Comparison
Develop a Pairwise Matrix
- Each of the squares in the matrix at right represents the pairing of two items (where the numbers intersect).
- In this example, the list includes five items; the top square (shaded) represents the pairing of item 1 with item 2.
Rank each pair of items
- For each pair of items, the team should reach a consensus on which of the two items is preferred over the other.
- As the team completes each of the comparisons, the number of the preferred item is recorded in that square, until the matrix is completely filled in.
Count the number of times each item appears in the matrix.
- Using the filled-in matrix (on the far right above), count how many times each item is listed in the matrix, and record the totals in the ranking matrix (at right).
Rank all of the items
- Rank the items based on how many times they appear in the matrix.
- To break a tie between two items appearing the same number of times, look at the square in the matrix where the two were compared; the item appearing in that box receives the higher ranking.
AcqLinks and References:
- DAU Program Managers Guide