The overall quality of the 'Highest certificate, diploma or degree' variable from the 2006 Census is acceptable. However, users of the 'University certificate or diploma below the bachelor level' category should know that an unexpected growth in this category was noted compared to the 2001 Census.
In fact, in the 2001 Census, 2.5% of respondents aged 15 years or over declared such a diploma, compared to 4.4% in 2006, representing 89% growth. This phenomenon was not found in other sources like the Labour Force Survey.
We recommend users interpret the 2006 Census results for this category with caution.
For more information on factors that may explain such variances in census data, such as response errors and processing errors, please refer to the 2006 Census Dictionary, Appendix B: Data quality, sampling and weighting, confidentiality and random rounding.
More information will be available in the Education Reference Guide, 2006 Census, to be published later in 2008.