An Overview of the History and Methodological Aspects of Psychometrics

Introduction: The use of psychometric tools such as tests or inventories comes with an agreement and acceptance that psychological characteristics, such as abilities, attitudes or personality traits, can be represented numerically and manipulated according to mathematical principles. Psychometrics and its close relation with statistics provides the scientific foundations and the standards that guide the development and use of psychological instruments, some of which are tests or inventories. This field has its own historic foundations and its particular analytical specificities and, while some are widely used analytical methods among psychologists and educational researchers, the history of psychometrics is either widely unknown or only partially known by these researchers or other students.Objectives: With that being said, this paper provides a succinct review of the history of psychometrics and its methods. From a theoretical approach, this study explores and describes the Classical Test Theory (CTT) and the Item Response Theory (IRT) frameworks and its models to deal with questions such as validity and reliability. Different aspects that gravitate around the field, in addition to recent developments are also discussed, including Goodness-of-Fit and Differential Item Functioning and Differential Test Functioning.Conclusions:This theoretical article helps to enhance the body of knowledge on psychometrics, it is especially addressed to social and educational researchers, and also contributes to training these scientists. To a lesser degree, the present article serves as a brief tutorial on the topic.