Expectation confirmation theory

Expectation confirmation theory (or ECT) is a cognitive theory which seeks to explain post-purchase or post-adoption satisfaction as a function of expectations, perceived performance, and disconfirmation of beliefs. The structure of the theory was developed in a series of two papers written by Richard L. Oliver in 1977 and 1980. Although the theory originally appeared in the psychology and marketing literatures, it has since been adopted in several other scientific fields, notably including consumer research and information systems, among others.