On the Use of Paired Comparisons to Construct Group Preference Scales for Decision Making

Polling opinion is a common group activity. Scaling tools can be used to provide a more precise presentation of opinions than traditional polling/voting. The interval scale of items constructed by scaling tools can aid participants in finding the current disposition of a group. We consider Thurstone’s law of comparative judgment as well as a weighted digraph ranking system for building group scales from pairwise comparisons. Assumptions for computing scales are reviewed together with issues and limitations of applying these scaling methods in groups. Results from a classic experiment and simulations by both methods are compared. We also made recommendations on choosing scaling method based on theoretic and practical consideration.