Enumeration Districts are not standardised units and can change from one census to another. They are defined by the Census Offices according to specific criteria intended to provide approximately equal workloads for enumerators. It takes into account such factors as:
What this means is that enumerators in more 'difficult' and challenging areas should have smaller EDs.
More can be learnt about the enumeration process in 2001 by viewing CHCC Unit 4: Census 2001: the Enumeration Process. [Note: This link opens in a new window]