 During this stage, statistical pattern recognition is used to identify the attribute combinations that the examinee is likely to possess based on the observed examinee response relative to the expected response patterns derived from the cognitive model.Prior to any further analysis, the cognitive model specified must accurately reflect the cognitive attributes used by the examinees.It is expected that there will be discrepancies, or slips, between observed response patterns generated by a large group of examinees and the expected response patterns.