INVESTIGATING THE CONSTRUCT VALIDITY OF “STRUCTURE AND WRITTEN EXPRESSION” SECTION OF TOLIMO THROUGH FACTOR ANALYSIS

This study aimed at investigating the construct validity of a nationwide large-scale English proficiency test (TOLIMO: The Test of Language by the Iranian Measurement Organization) which has been developed and administered by the Ministry of Science, Research, and Technology of the Islamic Republic of Iran: National Organization for Educational Testing (NOET). In this study, Factor Analysis was used to examine the construct validity of the test. To conduct the study, the performance of 154 examinees on 50 multiple-choice items of “structure and written expression” section of 77th administration of TOLIMO was examined. The data obtained from the “structure and written expression” section were subjected to an Exploratory Factor Analysis (FA). The results of FA revealed that eleven factors represent the underlying structure of TOLIMO. All in all, the results and findings of the study indicated that the “structure and expression” section of TOLIMO really measures what it supposed to measure and the scores of this section can be interpreted as real indicators of examinees’ ability level in structure and writing. The findings imply that the test demonstrated construct validity.