China is taking its once-a-decade census, sending six million enumerators door-to-door, and will attempt to count people where they actually live, rather than where their households are officially registered. This represents a change from the methodology that has prevailed since the Peoples Republic of China was founded in 1949.

Major challenges during the 10-day enumeration period will include determining China’s true number of migrant workers, who have helped fuel economic growth but who do not necessarily want the central government to know where they live. In an effort to count all children, the government has promised reduced fines for parents who have violated China’s one-child policy if they come clean to census-takers.

Beyond those particular challenges, Chinese officials say they face growing concerns about personal privacy rights, an issue that also hampers census-taking in many other nations. In an attempt to address those concerns, the census form does not ask about income or religion. According to the Associated Press, the names and photos of census-takers are posted on neighborhood bulletin boards to help residents avoid scam artists posing as enumerators.

For the first time, the census will include people born in other countries, not just Chinese nationals. The count of foreigners will exclude people on short business or tourist visits, according to Xinhua, the national news service.

Most people surveyed will be asked to answer 18 questions, but 10% of the population will be given a 45-question long form. Foreigners will be given an eight-question survey.

The main results from the census will be released in April. Estimates for the size of China’s population range up to 1.5 billion. The last census, in 2000, put the nation’s population at 1.295 billion.