The calibration and cross-modal validation of ratio scales of political opinion in survey research

Abstract

The aims of this paper are twofold: first, to set the ratio scaling of opinion in perspective by reviewing a series of laboratory and field experiments designed to build and validate ratio scales of political opinion; and second, to report in detail on the development of calibration procedures designed to obtain proportional judgments from respondents in a national survey. Paralleling explicitly a psychophysical paradigm established for the scaling of physical continua, these studies demonstrate that (1) the paradigm can be adapted to the scaling of sociopolitical opinions; (2) two measures suitable for use in surveys-magnitude estimation and line production-satisfy established psychophysical criteria for valid measures of response; (3) survey respondents can and do make reliable ratio estimates of strength of opinion; (4) scales measuring strength of political support, which are derived from the magnitude and line estimates of survey respondents, match closely the support scales derived in laboratory and field tests using such physical response modalities as handgrip and sound pressure; and (5) these calibration procedures can be incorporated in national opinion surveys. These results, especially the successful move from the laboratory to a conventional survey setting, provide social and behavioral scientists with a technique for generating response data that meet stringent measurement requirements. The calibration procedures described constitute a social metric that will enable researchers to test functional hypotheses in a more rigorous manner than is possible employing alternative scaling procedures.