Paired comparison method

Ranking becomes easier and reliable under the paired comparison technique. Each of the workers is compared with all other workers in the group; for every trait, the worker is compared through all other employees. For instance, when there are five workers to be compared, after that A's performance is compared with that of B's & decision is arrived at as to whose is worse or better. Next, B is also compared with all of the others. As A is already compared with B, this time B is to be compared with just C, D and E. By this method, while there are five workers, fifteen decisions are made (comparisons). The number of decisions to be made may be determined through the help of the formulae n (n-2). Ranking the workers by the paired comparison method can be illustrated as given in the Box 3.

For many individual traits, paired comparisons are made, listed and then rank is assigned to each of the worker. Though this method appears to be logical, this is not applicable when a group is big. When the group becomes too big, the number of comparisons to be made can become frighteningly excessive. For example, when n=100, comparisons to be made are 100 (100-2) = 100 (98) = 9800.

 Trait: 'Quantity of work'

Box: Employee Rated