As we all know, DNB CET had a multiple day exam pattern. For calculating the ranks in such exams the Item response theory is used. This same theory will be applied for making rank list of DNB CET, as published by natboard on its website... Read more about the notice here . If you are curios to know more about this system of marking read the details here... Item response theory From Wikipedia, the free encyclopedia In psychometrics, item response theory (IRT) also known as latent trait theory, strong true score theory, or modern mental test theory, is a paradigm for the design, analysis, and scoring of tests, questionnaires, and similar instruments measuring abilities, attitudes, or other variables. It is based on the application of related mathematical models to testing data. Because it is generally regarded as superior to classical test theory, it is the preferred method for the development of high-stakes tests such as the Graduate Record Examination (GRE) and Graduate Manag...