PAIRCOMP (Paired Comparison)
The PAIRCOMP (paired comparison) program administers the paired comparison experiment on a personal computer that presents the pairs of items on the monitor in a unique random order to control for order effects. Items are presented in pairs to one or more judges. The judge selects the item that best satisfies the specified criterion. Items can be anything including goods, services, and environmental conditions. This method can yield an interval-scale ordering of items along a dimension such as preference or importance. For example, items that are considered for forest improvements being judged by the general public and reveal the public's collective judgement of the relative importance of the improvements. As well, when the items include both monetary amounts and goods, the method can yield an estimate of monetary value of the goods.
The items entered into the program appear side-by-side on the monitor with their position (right or left) randomized. The respondent enters a choice by pressing the right or left arrow key and can correct a mistake by pressing the backspace key and then selecting the other item.
At the end of the paired comparisons, the program repeats in random order those pairs for which the individual's choise was not consistent with the dominant preference order as defined by the preference scores. The program also randomly selects ten consistent pairs for retesting. The individual pairs in these two sets of repeat choices are randomly intermixed with nothing to indicate to the respondent when the original pairs end and the repeats begin. The program records the time taken to enter each choice.
The software is available to download, and runs on a personal computer with Microsoft Windows 95/NT.