Abstract
Psychometrics is a method to measure psychological phenomenon, and it is, “a scale of a mind” to grasp invisible psychological phenomenon. Psychometrics makes possible to compare individual difference of psychological phenomenon by converting answers for several questions into a score. In the process of psychometrics development, the target psychological phenomenon needs to be defined as a theoretical construct, and a standardized procedure is required to develop question items that reflect the construct. Particularly important feature of the psychometrics is to measure the target psychological phenomenon accurately and appropriately. “Reliability” and “validity” are the indicators to determine accuracy and appropriateness of the psychometrics. This report provides basic knowledge necessary to utilize a psychometrics to clinical practice and research study focusing on development procedure and reliability and validity.
