The data you require, or similar data, may already exist within your organisation but it may need to be geocoded. Many commercial companies produce spatial data and it may be speedier and better value to purchase such data rather than collect it yourself.
When considering using spatial data collected by others it's important to consider the quality of the data and its limitations. Such information should be available in the metadata.
Is the data collected at the appropriate scale for your application? For example, a postal address could provide sufficient spatial accuracy to deliver letters, but calculating land valuation requires much more precise boundary definition.
If the data has been aggregated, is this appropriate for your application? For example, a ward-based dataset cannot then be used to analyse data at Primary Care Trust (PCT) level.
- Is the data spatially accurate?
- Temporal issues: is the data current?
- Is the data complete? Are there any erroneous attributes?
- Is the data consistent? For example, are naming conventions consistent? Do features of the same type have the same descriptive data?
Geodemographics
Socio-economic data is used by a number of commercial vendors who combine census information with other datasets to produce neighbourhood profiles classifying particular areas for marketing purposes. This ability to recognise particular markets based on geographical datasets is called geodemographics.
National licence agreements
A number of national licence agreements exist for the provision of spatial data. See:
www.ordnancesurvey.co.uk