A controversy has been brewing ever since the Ministry of Welfare sought the inclusion of caste statistics in the census questionnaire saying this information was required for implementing the Mandal commission recommendations on reservations.

``Caste data collection can never be a happy or a perfect exercise,'' Vijayanunni told journalists here.

The problem lies in the over 68,000 caste categories that exist in the country, of which the Anthropological Survey of India had identified and listed some 7,331. Of these too, the ``People of India'' study bythe ASI had located only 4,365 castes.

The castes would be further divided along the lines of sub-castes, sub-communities, gotras and lineages, all making for a complicated system reflecting the stratification in Indian society.

``It is not our job to classify and identify castes and jatis,'' said the Census Commissioner, adding that census operations were an enumeration exercise, a collection of empirical data.

The world's largest census and administrative exercise will begin in the second week of February 2001 and end three weeks later by the sunrise of March 1.

Other problems that could arise when including caste is the greater probability of subjectivity entering the collection of data leading to unreliability of census data, he said.

Around 2 million enumerators, drawn from the ranks of school teachers and government employees, will be pressed into service to interrogate 200 million households on economic, educational, demographic and socio-cultural details to give a comprehensive statisticalpicture of the population of the country at the beginning of the next millennium.

On the question of immigrants, the census commissioner clarified that the 2001 census will not have data relating to immigrants from neighbouring countries.

About census in militancy-affected areas in the country, he said ``it was unfortunate that Assam was left out in 1981 and Jammu and Kashmir in 1991 due to law and order problem. But this time we would try our level best to conduct the process all over the country.''

On the controversy over non-availability of proper data in previous census' about women, especially in rural areas, the commissioner pointed out that this had been an area of concern and this time the questionnaire is being redesigned and maximum publicity will be given before the census so that people come forward with more information. ``Our past experience shows that there has been poor response from women, especially in some parts of Punjab, Haryana and Uttar Pradesh. This time our efforts will be toimprove on that count,'' he said.

On the use of information technology, he pointed out that the census commission has got a website operational in the Internet with about 3,700 clicks about the census and would keep on feeding the latest information. ``We will be using the state-of-the-art technology that would be available in the year 2000 for census collection and preservation of data,'' he added.