Instrumentation and measurement in educational assessment

To engineers accustomed to the sensors and other instrumentation typically discussed in this magazine, a college entrance exam might hardly seem like measurement. Yet the construction and evaluation of educational instruments rest on familiar foundational measurement concepts. However, while engineering instruments measure physical properties, educational instruments measure psychological characteristics, such as students¿ knowledge, skills, and abilities. In this article, I introduce educational assessment from a measurement perspective, highlighting how key measurement concepts play out when the measurand is psychological.