The KET test has four skills – reading, writing , listening , and speaking. The test format is framed within theoretical construct as it has been defined. For language tests therefore, this is the theory of language ability and for teaching qualifications it is the theory of teaching
knowledge and practice. Construct validation is therefore about investigating whether the performance of a test is consistent with the predictions made from these theories construct validation activities can include those where experts analyse the content of tasks, those that involve study of the cognitive processes of candidates and those involving statistical analysis of underlying factors shared by a series of tasks or items. One statistical method used is Structural Equation Modelling.