GeoConvert: Creating that Spatial Relationship

David RawnsleyMimas, University of Manchester

Overview

GeoConvert is an online geography matching and conversion tool for UK academics.

GeoConvert allows registered users to obtain and manipulate complex geographical and postcode data in a straightforward way.

A solution to a specific UK problem but it can be applied to any country.

The Problem

Many types of geography in the UK

AdministrativeElectoralPostalHealthEuropeanCensusStatistical

A Little UK Geography

Counties, Districts, Unitary Authorities - 1998

Strategic Health Authorities - 2006

Parliamentary Constituencies 2005

Further Complication

Wales ScotlandEngland

UA

ST Ward

CAS Ward

Ward

Unitary Authority

ST Electoral Division

CAS Postcode Sector

MSOA

LSOA

LLSOA

Intermediate Zones

English and WelshOutput Areas

ScottishOutput Areas

Northern IrishOutput Areas

GOR

District

County

Council Area

Data Zones

District Councils

CAS Electoral Division

Northern Ireland

UK

ST Postcode Sector

A Partial Solution

The NSPD

Produced by the Office for National Statistics

A long list of UK PostcodesAlso has other geographical zonesPostcode metadataNew version every quarter

Problems With The NSPD

It’s huge – 1.37 Gb at last count It’s cumbersome –

flat file with many rows or basic Access database

Horrible variable names – ‘OSHLTHAU’ It keeps changingVery little support from ONS

Why can’t someone tame it?

Our Hero At Last

What is it?Online web based access to NSPDRange of functions Provides a framework for integrating

dataRegularly updatedHelp and support provided

• FAQs• Original documentation• Glossary• User Guides

GeoConvert

What Does It Actually Do?

3 functions

Postcode related information

Geography matching

Geographical data conversion

Why Should I Use It?

Prizes! It enables datasets to be linked much

more easily It enables researchers to link their

own data to many more datasets It enables data to be linked

historically It allows users to quickly and easily

get access to widely used deprivation and classification data

How Does It Do It?

Postcode information direct from NSPDUse postcodes as a population proxyDissection and re-aggregation of filtered

postcodes between zones to achieve measure of proportional distribution of population

Lots of complicated database stuffLots of complicated interface stuff

UK specific but the solution can be applied to any country

Isn’t Some Of That A Bit Dodgy?

Dependent on accuracy of ‘how much?’ and ‘where?’

Boundary fuzziness due to unique allocation of postcodes

Ideal data is population related with homogenous distribution• male, female = good • clusters of cancer patients = bad

Based on current population• current to historical works best

Partial input = partial output

What Might It Do Next?

A better population proxy?Different population proxiesMore metadataConfidence measuresStandards based XML outputIntegration with external data sourcesMachine to machinePipetastic

http://geoconvert.mimas.ac.uk