Web Access to Census Interaction Data John Stillwell and Oliver Duke-Williams Centre for Computational Geography University of Leeds, Leeds LS2 9JT Paper presented at XVI AESOP Congress, Track 6: Information Technology in Planning, Volos, July 2002

Focus §The provision and development of a Census Interaction Data Service (CIDS) §The development of a web-based information system (WICID) that allows researchers to extract data on interaction flows between origins and destinations

Presentation §The challenge: aims and objectives §Census based interaction data sets §Importance of interaction data in planning §System architecture and metadata structure §Features of the interface §Some examples of data extraction

Acknowledgements §Funded by ESRC and JISC under the 2001 Census of Population Programme (Award number H ) §Began: 1 August 2001 §Ends: 31 July 2006 §Paul Boyle and Zhiqiang Feng, University of St Andrews

The Challenge §Aim is to increase the use of the Origin- Destination (interaction) data sets that will be produced as outputs from the 2001 UK Census (as well as the equivalent special migration and commuting data sets produced from 1991 and 1981 censuses)

Objectives §To provide users with access to existing census based interaction data sets (for 1991 and 1981) via the Internet §To develop an ‘user-friendly’ interface for query building and data extraction §To develop a flexible system that allows new data sets (e.g Census interaction data) to be added without any major system redesign

Objectives §To allow users the option of constructing queries that involve the selection of origin and destination areas at different spatial scales §To produce a library of popular sub-sets of interaction data for quick extraction and downloading §To provide facilities to download the data in alternative formats

Interaction Data Sets for 1991 Original data sets §SMS Set 1 (2 tables, 12 counts, wards) §SMS Set 2 (12 tables, 93 counts, districts) §SWS Set C (9 tables, 274 counts, wards) §Table 100 (2 tables, 47 counts, districts) Derived data sets §SMS Set 1 Tables 3-10 (adjusted by Rees and Duke- Williams) so-called SMSGAPS §SMS Set 1 Table 3 (adjusted by Simpson and Middleton) so called SMS-MIGPOP

Interaction Data Sets for 1981 §1981 SMS Set 2 (Male and female migrants between wards in 1991) §1981 SWS Set C (Five tables counts - of journey to work flows between wards in 1991) §all re-estimated for 1991 ward geography by Boyle and Feng as part of a Census Development Programme project

Importance of interaction data in planning §Interaction data sets are very important because they provide information on migration and commuting flows between small areas (wards) §e.g. migration data used for population estimation and projection by central and local government agencies §e.g. commuting data used to define TTWAs and in transport planning

System Architecture

Metadata Structure

Features of the WICID Interface Login in screen

WICID General Query screen

WICID Area Selection Tools

WICID List Area Selection Tool

WICID Data Selection Tools

WICID Data Selection Options

WICID Table Selection for 1991 SMS 2

WICID Variable Selection with Table 1 of 1991 SMS 2

WICID Data extraction

WICID Output Planner

WICID Output Previewer

Some examples of data extraction: Query 1: Migrants from Greece to GB by age

Age profile of migrants from Greece, Source: 1991 Census Crown Copyright: ESRC/JISC Purchase

Query 2: Migrants to districts in GB from Greece,

Districts receiving most migrants from Greece, Source: 1991 Census Crown Copyright: ESRC/JISC Purchase

Social structure of Leeds and surrounding districts using 1991 SWS

Query: Journey to work flows between zones by social class, 1991

Social class structure of commuters in Leeds and between Leeds and surrounding districts, 1991 Source: 1991 Census Crown Copyright: ESRC/JISC Purchase

Source: 1991 Census Crown Copyright: ESRC/JISC Purchase Proportions of commuters to Central Leeds from other wards and surrounding districts by social class, 1991 Professional Managerial and Technical

Source: 1991 Census Crown Copyright: ESRC/JISC Purchase Skilled Non-manual Skilled Manual

Source: 1991 Census Crown Copyright: ESRC/JISC Purchase Partly Skilled Unskilled

Conclusions/Next steps §CIDS now up and running §Flexible metadata structure of WICID will allow 2001 Census results to be included in the system §WICID will be used to verify the 2001 data in 2003 §Mapping option for geographical area selection now being developed §Analysis and modelling facilities intended but raises difficult questions