It highlights points to consider when comparing census outputs from 2001 with those being published for the 2011 Census.
An annex to this report deals more specifically with the differences in the outputs being published in 2011 and their equivalent in 2001 and the extent to which direct comparison is possible.
A further guidance note provides more detail on the comparisons that can be made between 2011 and 2001 outputs at smaller geographic units.
Comparability of the census questionnaire in Northern Ireland between 2001 and 2011