New Delhi, Feb 24 Preparations for conducting the 2011 population census have commenced, and the process will begin this April, Parliament was informed on Tuesday.

"The formal notification of the intent of the government of India to conduct the census in 2011 (has been released)," Minister of State for Home Affairs Ajay Maken said in a written reply in the Lok Sabha.

Maken said the census operations are conducted in two phases. "The first phase, which is house-listing and housing census, precedes the population enumeration by about eight to nine months."

A framework for population enumeration, data on housing, amenities and the assets available with each of the households is prepared in the house-listing and housing census.

"The house-listing and housing census would be conducted from April to September 2010. The time schedule in each state is being notified," he said.

"The population enumeration will be conducted in February-March 2011," Maken added.

In the second phase of population enumeration, data on various socio-economic and demographic parameters like age, sex, literacy, religion, languages known, economic activity status and migration is collected. The pre-testing of the census questions was done last year.

"Based on the feedback of pre-test, the questions to be canvassed during census have been finalised by the technical advisory committee," Maken said.

"The government has approved the final set of questions," he added.