How was data collection organised?

A 4 tier fieldwork structure was used to conduct data collection in the 1991 Census: 135 Census Area Managers supervised 2,562 Census Officers, who supervised 7,750 Assistant Officers, who supervised 117, 600 enumerators. Each enumerator was responsible for delivering and collecting the census to households in an Enumeration District (ED), the size of which was based on the number of households that could be covered by an enumerator in the time period. To reflect the fact that some areas were harder to enumerate than others, EDs (in England and Wales) were graded into seven categories of expected difficulty. The hardest contained 50-120 households, the easiest 175-250.