Instrument construct is one of the most important issues in conducting research. Without proper consideration in tackling the issue, it is difficult for the instrument to be considered as valid and reliable. If construct validity is accurate, then it will provide a clearer and more precise descriptive analysis on the concepts being investigated. The most important criteria that need to be considered in answering the construct validity are reliability and validity. In traditional measurement model, the understanding of reliability and validity is totally different from the one offered by Rasch model. Regardless of the difference, an internal consistency is still widely being used as the primary method to measure the item sampling. Using this model, local dependence and item fit are most considered in getting valid, reliable, and consistent, hence its significance. Finally the study applies goodness of measure purposely to answer issues related to validity and reliability tests. Principal components analysis was carried out to test the construct of questionnaires used in the study.
