Determining the Construct Validity and Reliability of Philanthropic Behaviour Scale using Rasch Model

Abstract

This paper empirically analyzes the validity and reliability of philanthropic behaviour measurement items using Rasch Model. The survey is grounded on the Theory of Planned Behavior (TPB) but extends to include other relevant factors, thus the items’ validity and reliability need to be confirmed. The instrument consists of 40 items vested under seven dimensions; attitude, subjective norms, perceived behavioral control, altruism, financial stability, religiosity and trust. Based on the analysis, item polarity indicates that the point measure correlation for the 40 items measuring determinants of philanthropic behavior is between 0.26 to 0.60. Overall item reliability and item separation is 0.97 and 6.05 respectively, while for person reliability and person separation is 0.85 and 2.34 respectively, considered good and productive for the intended measurement. In terms of items fit, results show that only five items are found misfit and need further scrutinization prior to removal of the items.