Dimensions of political ideology. An operational approach from Item Response Theory

Although political ideology is a core concept for contemporary political psychology, divergences persist in the literature regarding its structure and operationalization. This paper assesses the psychometric properties of the Escala de Ideologia Politica [Political Ideology Scale] operationally, that is, considering people's positioning regarding different political issues. For this purpose, a probability sample was taken from the population of Cordoba, Argentina (N = 444) and the psychometric properties of this scale were tested by applying Item Response Theory. A two-dimensional structure with two independent axes -Conservatism and Progressivism- was found, each with interval properties and satisfactory model fit. Furthermore, political ideology was correlated with social values, in a way that is consistent with the previous empirical evidence. This provides evidence of predictive validity. In sum, although the psychometric properties of the Political Ideology Scale will be further studied, this paper represents a significant contribution, due to the scarcity of ecologically valid instruments of operational ideology.