Ottawa

’Exercise caution’

This year’s census data comes with an asterisk.

The agency released its final tranche of the 2011 census last week, focusing on languages, but it included a big warning that cautions data users about comparing key facts against censuses of the past. “Data users are advised to exercise caution when evaluating trends related to mother tongue and home language that compare 2011 census data to those of previous censuses,” Statistics Canada states bluntly in a box included in its census material.

Those are strong words for a statistical agency, since they raise profound questions about how the data can be used reliably to come to conclusions about language trends. Officials have undertaken a thorough investigation, with a report to be published shortly. “There are a lot of questions and responses that don’t seem to add up,” said Doug Norris, the chief demographer for Environics Analytics and formerly a census manager at the agency.