Application de la théorie de réponse aux items à l'analyse d'échelles d'attitude

Abstract

Application of Item Response Theory to the Analysis of Attitude Scales. The article presents Item Response Theory (lRT) and illustrates its application to the analysis of two measures of work-related attitudes -- value given to social aspects of the job and satisfaction with extrinasic aspects of the job. Results of IRT analysis show that extrinsic satisfaction cannot be measured in the same way among contract professionals as opposed to regular employees. Using information provided by IRT analysis. it appeared that satisfaction with salary cannot be included in a scale measuring extrinsic satisfaction because it does not contribute to the measure in the same way for the two groups of employees: furthermore, satisfaction with social benefits may be included in the scale only if discrimination and difficulty parameters are allowed to vary across groups. Analyses of variance using theta scores estimated in this way give statistical conclusions that are notably different form those obtained using traditional additive scores and permit refinement of interpretation.