The National Medical Commission Act recently passed by the Parliament has been a source of concern for multiple reasons:

One of which is the National Exit Test. Chapter IV Section 15 (5) of the act states: "The National Exit Test shall be the basis for admission to the postgraduate (P.G.) broad-specialty medical education in medical institutions which are governed under the provisions of this Act or under any other law for the time being in force and shall be done in such manner as may be specified by regulations."

Section 15 (1) of the chapter (IV) of the act defines the National Exit Test and assigns another purpose for the test. It states, "A common final year undergraduate medical examination, to be known as the National Exit Test shall be held for granting a license to practice medicine as medical practitioners and for enrolment in the State Register or the National Register, as the case may be."

Thus, the same test is expected to serve both the purposes of licensure as well as the selection for PG admission. The licensure test is a qualifying test whereas the PG admission is a selection test. The objectives of the two tests are different, and accordingly, the type of questions, test construction interpretation of scores, and assessment of their reliability and validity are different. Here, I touch upon some of these.

The purpose of a qualifying medical examination is to permit making a judgment whether a given medical student is competent enough to be a safe practitioner. Does he have such a minimum level of knowledge and skills that allowing him to practice medicine does not pose a risk to society? However, the purpose of a selection or PG admission test is to properly rank the candidate, so that his relative position with reference to other candidates is appropriate. All the candidates may be meeting the minimum standards, in fact, they may all be much above or below the minimum standards but between them, the relative position should be correct.

A multiple-choice question for a qualifying test may be so designed that all the candidates who meet the minimum standards answer it correctly, whereas such a question is not helpful in ranking candidates because all of them answer the question correctly. A multiple-choice question for a selection test should be so designed that it differentiates among the candidates; those with higher ability are able to answer it correctly and those with lower ability are not able to answer correctly. Educational psychometricians measure this property of the question as to its "discrimination index" (I prefer to call it "differentiation" because of the negative social connotation of the term discrimination but in education, the term discrimination is deeply ingrained).

A test characteristic closely related to discrimination is "difficulty" level. Questions that are too easy or too difficult are not capable of discriminating between high and low achievers, and, therefore, such questions produce score distribution that makes it hard to identify interindividual differences reliably.

For discrimination, the ideal difficulty level is moderate. Stated quantitatively, the mean score of a test with moderate difficulty should be halfway between a perfect score and the mean chance score. Writing such a multiple-choice question (or any other form of a question) requires considerable skill to develop and construct a set of questions that achieve the appropriate level of difficulty.

For a qualifying examination, the question writer is not free to influence the difficulty level directly. To the extent that difficulty is influenced, the relevance of the test may suffer. Test score of such an examination should differentiate between a competent and safe practitioner and incompetent or unsafe practitioner. Educational psychometricians call the interpretation of qualifying examination score a criterion-referenced interpretation whereas that of selection examination score a "norm-referenced interpretation." These terms are also used frequently by educators to describe kinds of tests, for example, a norm-referenced test is one that permits the user to make norm-referenced interpretations from its scores.

R. L. Ebel,\[[@ref1]\] a renowned educationist has said, "it is seldom advantageous to interpret given test scores in more them one way; good tests tend to be built to optimize the user\'s ability to make only one type of interpretation. As a result, there are important variations in the procedure adopted for constructing tests that will yield one type of interpretation rather than the other."\[[@ref1]\] The proposed national exit examination aims to achieve both norm-referenced and criterion-referenced interpretation, this is likely to compromise the objectives set out in the act.
