The Evolving Influence of Psychometrics in Political Science
This article outlines how the measurement of political issue spaces has developed in the past eighty years through borrowings from psychometrics (scaling, factor analysis, and unfolding), additions from political science theories (the spatial theory of voting and ideal points), and confronting the special problems of political survey, roll-call, and interest-group ratings data. Psychometrics is a subfield of psychology devoted to the development, evaluation, and application of mental tests of various kinds. In the 1980s, political scientists began combining techniques from econometrics and statistics with approaches developed by psychometricians. The effect of psychometrics displays no sign of abating in political science. The level of sophistication of psychometric applications in political science has steadily increased in the past twenty years.