The marathon task of counting and profiling India's estimated 120 crore (1.2 billion) people began on Thursday with President Pratibha Patil being the first citizen to be enumerated.
Home Minister P Chidambaram, Home Secretary GK Pillai and census officials visited the Rashtrapati Bhavan in the morning and collected details from the president, a symbolic inauguration of the process to count and create a data base of each citizen.
"My name is Pratibha Devi Singh Patil and my permanent address is Jalgaon, Maharashtra," the president said, sharing her details with a census enumerator.
As the first citizen of India, Patil then signed the census form and urged people in the country to "wholeheartedly take part in the exercise and cooperate with census officials as it is in the nation's interest and for the benefit of the people of this country".
The officials led by Chidambaram later visited Vice President Hamid Ansari at his 6, Maulana Azad Road residence to enumerate him and his family.
The gigantic exercise of the Census 2011, which will be the 15th headcount of India's population since 1872, will be undertaken in two phases to create a database on demography, economic activity, literacy and education, housing and household amenities, urbanisation, fertility and mortality, Scheduled Castes and Scheduled Tribes, language, religion and migration.
The census is an important exercise that compiles the socio-economic indicators of people. For the first time, officials would step beyond the demographics and economic activity and would collect details, including ownership of mobile phones, computers, internet, and availability of treated or untreated drinking water facility.
Over the next year, some 2.5 million census officials will visit households in more than 7,000 towns and 600,000 villages in the country.
They will first begin the process of house listing, which records information on homes. The headcount of people will take place from Feb 9-28, 2011. The full census results will be released in mid-2011.
Home Minister P Chidambaram described the process as "the biggest exercise since humankind came into existence".
The census 2011, which will cost the government Rs.2,209 crore, is also important as as the government also intends to create the National Population Register (NPR), a comprehensive identity database that will facilitate the creation of a biometrics-based identity system in the country, allowing identity cards for all citizens above 15.
"We have just enumerated the president of India as the first citizen of India to symbolically inaugurate this massive exercise... We will be issuing identity cards to 1.2 billion people," Chidambaram told reporters as he urged civil society leaders to publicise and create awareness about the importance of this exercise.
The census is the only source of credible data base in India that the government uses to formulate its policies. The data is also used for research by private companies to identify markets for their products.
The entire exercise is being done under statutory provisions of the Census Act, 1948. And if anyone fails to cooperate, the person can be fined or punished.
Around 12,000 tonnes of paper will be utilised for printing 64 crore census forms and 50 lakh instruction manuals. The census forms are printed in 16 languages and the instruction manuals in 18.