Operationalizing the theory of human values: Balancing homogeneity of reflective items and theoretical coverage
Schwartz’s theory of human values, as operationalized using di_erent instruments such as the Portrait Values Questionnaire (PVQ), was confirmed by multiple studies using Smallest Space Analysis (SSA). Because of its success, a short version of the PVQ was introduced in the European Social Survey (ESS). However, initial tests using Confirmatory Factor Analysis (CFA) pointed to low discriminant validity of the 10 basic values: The correlations between values next to each other in the two-dimensional space described by SSA were close to or greater than 1. In response, one research stream suggested combining the factors with low discriminant validity. Another stream suggested that the problem was not low discriminant validity but rather misspecifications in the model. Analyses of the short Portrait Values Questionnaire of the ESS confirmed the latter view.
This paper demonstrates that the problems of the short version of the PVQ exist in the full 40-item PVQ as well. Based on SEM analyses of the items of the full PVQ, we propose that it can provide measures of 15 more narrowly defined values with good discriminant validity. Our proposal respects the conceptual complexity of the values theory while avoiding contamination of composite scores. It can be expected that the improved measurement of 15 values will increase their predictive power. The presence of some single items suggests the extension of the value theory and scales to encompass more than 15 values. Implications for further development of the scale are drawn.