Genealogists and historians have sought clarification on whether a streamlining of the Canadian census provisions will mean that some types of data will no longer be published.

Following complaints on personal privacy grounds about questions on commuting time, child care and religious beliefs, the ruling Conservative government scrapped the mandatory long census form for the forthcoming 2011 census. A voluntary national household survey has been introduced in its place.

Unlike census data, national household survey data will never be made public. But although the Canadian information ministry has issued assurances that "long-form data will be released", Statistics Canada says it has not been advised of legistative changes that would be required to open national household survey data to the public.

The scrapping of the mandatory long census form – which went to one in five households – has created other headaches for Statistics Canada too. The agency says it will have to work very hard to get a comparable response from a voluntary survey.

Assistant chief statistician Rosemary Bender acknowledged that "we might not get the same level of detail … the agency has never undertaken a voluntary survey of this size".