The One-Parameter Rasch Model: a Bridge Between Test Theory and Assessment Practice
Uzunova-Dimitrova Boryana · Journal of Lifestyle and SDGs Review · 2025
Objective: The study aims to demonstrate how the one-parameter Rasch model builds upon traditional valuation techniques. The approach provides a solid foundation for equitable and comparable value through measurement invariance and objectivity. The study also seeks to emphasize how crucial the model is for arriving at well-informed and rational valuation conclusions. Theoretical Framework: The Rasch model, a representation of item response theory (IRT), serves as the foundation for the study's theoretical framework. By analysing the connection between task complexity and participant competency, the model offers a scalable and impartial way to quantify performance. It differs from traditional test theories in that it is founded on the ideas of mathematical rigour and measurement invariance. Also taken into account are the fit statistics, Infit and Outfit, which determine if the test questions are well-structured and, thus, whether the evaluation will be impartial and fair. Method: The paper examines the one-parameter Rasch model both theoretically and empirically in the context of social science and educational evaluation. The focus is on the model's primary features, including scalability, measurement invariance, and objectivity. To determine if the empirical answers are compatible with the theoretical model, an evaluation of the empirical data is conducted using fit statistics, such as Infit and Outfit, in addition to a critical examination of the literature and conceptual analysis. This proves the validity and dependability of the measurements made using the Rasch model. Results and Discussion: The findings demonstrate that the Rasch model offers consistent, impartial measures that are not influenced by the particular respondents or tasks. The trustworthiness of the evaluation is attested to by fit statistics (Infit and Outfit), which validate the strong agreement between the model and the actual data. The approach effectively pinpoints possible trouble spots and offers a foundation for more impartial and accurate interpretations of the findings. Research Implications: The study's findings support the significance of the one-parameter Rasch model as a trustworthy evaluation instrument in the social sciences and in the field of education. The model expands on traditional methods and facilitates well-informed evaluation choices because of its impartiality and the potential for comparable measures. The model's validity and usefulness are further reinforced by the use of fit statistics. Originality/Value: The study makes a contribution by highlighting the Rasch model's benefits over traditional methods and highlighting its capacity to produce comparable and objective measurements. The use of fit statistics (Infit and Outfit) as a diagnostic and assessment-improvement tool is another innovation.