No technique of random sample has, so far as I can find, been developed in the United States or elsewhere, which can compare in accuracy or in economy… - Prasanta Chandra Mahalanobis

Population in India is widely differentiated in ethnic composition, geographical and climatic conditions, social and cultural stratification, as well as by differences in economic status. Differential fertility therefore assumes a far more complex picture in India than anywhere in the world. Ethnic. geographical. socio-cultural and economic dilferences give a four-fold patterning with many complicated interactions. It is essential therefore to study different population groups separately.

I need hardly say that I refer to the emergence of a statistically competent technique of Sample Survey, with which I believe Professor Mahalanobis name will always be associated.

In the absence of social awareness and appreciation of the scientific objectivity among sufficiently large number of civil servants or political leaders,the need of validity has not yet been accepted in the official statistical system in India. Ofcial statistics in India is treated as an integral part of the dministrative system which is regulated by the principle of authority. Approval of statistical estimates at a high level of authority is accepted as a bstitnte for validity in many ases there is continuing opposition to independent cross-hccks for the validity of the data. Officials have the feeling that two independent estimates, which might differ would be confusing and, in fact unthinkable; therefore independent cross-checks in statistics should be eliminated.