Amos is a computer program for performing structural equation modeling (SEM) and mean and covariance structure analysis. Its full name is IBM SPSS Amos, with Amos standing for “analysis of moment structures.” It was developed by the Amos Development Corporation, which is now owned by the IBM SPSS Corporation. Because of its easy-to-use functions, it has become a popular SEM program. Many educational researchers use it to validate measures and test hypotheses. This entry describes the basic features and functions of Amos and illustrates its application in education research.