12 Summary

Over the course of this eModule you have seen that geography is used throughout the ESRC Census Programme. We have seen that within the resources that are available through the ESRC Census Programme, references are made to different type of geography. We looked at some of these types of geography. These included Administrative, Electoral, Health, Statistical and Postal geographies. One of the most important types of Statistical geography was the geography of the census itself which changes every 10 years. Change was a theme that ran through each of our geography types.

Having looked at types of geography we then went on to see how geography is represented digitally as digital boundary datasets within a Geographical Information System (GIS). We noted that there are often peculiarities associated with the representation of census geographies within digital boundaries and that GIS datasets may be provided in different data formats.

Finally we saw that there are alternative representations of the geography as stored in a digital boundary dataset. This includes centroids, of which there are two types, population and geometrically weighted and geographical lookup tables. We saw that a geographical lookup table captures the relationship between two or more different types of geography. Postcode directories are an important example of geographical lookup tables.