These include exploratory factor analysis, principal components analysis (PCA), and confirmatory factor analysis. Confirmatory tests are the tests required to confirm the analysis. Diagnostic imaging for MALS is divided into screening and confirmatory tests. In the main analysis phase either an exploratory or confirmatory approach can be adopted. In a confirmatory analysis clear hypotheses about the data are tested. Confirmation bias (or confirmatory bias) has also been termed myside bias. Structural equation modeling software is typically used for performing confirmatory factor analysis. This can be done within a confirmatory factor analysis framework. Usually, the disease is diagnosed on clinical grounds, and no confirmatory laboratory testing is needed. Additional facilities started to conduct confirmatory testing. The combination of screening and confirmatory dRVVT reagents made identification of LA more simple. The role of confirmatory nerve conduction studies is controversial. The best confirmatory precipitation test for anthrax is the Ascoli test. Measurement invariance is often tested in the framework of multiple-group confirmatory factor analysis (CFA). It is used as a confirmatory test for syphilis infection.