Page "Census" Paragraph 10

Triple system enumeration has been proposed as an improvement as it would allow evaluation of the statistical dependence of pairs of sources.

However, as the matching process is the most difficult aspect of census estimation this has never been implemented for a national enumeration.

It would also be difficult to identify three different sources that were sufficiently different to make the triple system effort worthwhile.

The DSE approach has another weakness in that it assumes there is no person counted twice ( over count ).

In de facto residence definitions this would not be a problem but in de jure definitions individuals risk being recorded on more than one form leading to double counting.

A particular problem here are students who often have a term time and family address.