In order to make a meaningful comparison, instruments must have similar measurement qualities across settings. Research on measurement invariance has typically focused on internal structure of multi-item instruments and external relations. In the recent literature, researchers have paid attention to four forms of invariance. The researchs which include the measurement invariance tests can detect psychometric problems that result from cultural biases in item content, translation errors, acquiescence biases, and other factors. Also Statistical techniques to define and assess measurement invariance are helpful and useful to develop a framework for theoretical definition.