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

Updated: 7/15/2021

Rank: G9.5