Construct Validity of the Korean Dental Licensing Examination using Confirmatory Factor Analysis

Abstract

Confirmatory factor analysis based on a measurement model of a structural equation model was used to test the construct validity of 13 subjects in the Korean Dental Licensing Examination (KDLE). The results of 1,086 examinees who wrote the KDLE in 2004 were analyzed. The thirteen subjects were classified into 62 major categories and 122 intermediate categories. There were 364 items. A hierarchical model was constructed, including major and intermediate categories. The impact of the variables was determined by the standardized regression coefficient that related latent and measured variables in the measurement model. The KDLE showed a high goodness-of-fit with a root mean square error of approximation of 0.030 and a non-normed fit index of 0.998. When the latent variables for the major and intermediate categories were analyzed, the standardized regression coefficients of all of the subjects, with the exception of Health and Medical Legislation, were significant. From the result, we concluded that the 13 subjects showed constructive validity. In addition, the study model and data were very compatible. The subject Health and Medical Legislation had a low explanatory impact with respect to testing the ability of dentists to perform their jobs. This study suggests that similar psychometric studies are needed before integrating or deleting subjects on the KDLE, and to improve item development.