1. Working Group on Population and Housing Censuses
Luxembourg, May 2015
Item 3 of the Agenda
Update on the operation and use of the Census Hub

2. The Census Hub project Started as pilot project in early 2008
Developed in parallel with EU census legislation
Major collective achievement of the ESS
Great effort of coordination among Eurostat and NSIs (IT and statistical services)
First example of full implementation of SDMX
Innovative data transmission/dissemination tool based on the concept of “data sharing”

3. Reusability of the Census Hub
The Census Hub was developed as “generic solution”
Can be used in other domains by simply replacing the Data Structure Definitions of the underlying data
Opens a totally new approach towards data transmission and dissemination
Developing further solutions based on “data sharing” is now part of Eurostat IT strategy (DIGICOM project in the context of the ESS Vision 2020)

4. Performance and availability
A few countries had recurrent problems during the first months
Now availability close to 100%
Performance: in general good Main drawback: depends on the slowest node
Around seconds for small queries including all countries
Around 1-2 minutes for huge queries including all countries

5. Key issues for future steps
1) Maintenance of the system
Automatic monitoring and notification system
Problem identification and solution only possible in Member States
2011 census data need to remain accessible until 2025
Ensuring maintenance of the system is important to preserve the value of the investment

6. Key issues for future steps
2) Ensuring an agreed level of data quality
“Data sharing” requires a common understanding of data validation
Some data issues were identified during the quality check of census data
ESS strategy to set up a common policy on data validation (ESS.VIP Validation)
Possibility to include common validation rules for the 2021 census round

7. Monitoring users and queries
The Census Hub keeps a detail log of each query that is executed by users:
Hypercube number
Date and time
Type of user
Member States WS queried
Topics selected
Codes selected per topic
Provides a useful feedback about the relevance of the different topics/cross-tabulations
Input for the design of the new datasets for the 2021 census

8. Monitoring users and queries
Results presented at this meeting are just preliminary
Technical problems prevented us from analysing the log files for some hypercubes
Number of queries taken into account: about 16,000
Final results of the usage analysis will be presented at the June meeting of the TF on future censuses

9. No. of dimensions queried (not including AGE and SEX)

10. Most popular topics included in queries (not including AGE and SEX)

11. Disaggregation by AGE and SEX in queries involving the most popular topics

12. Most popular bivariate cross-tabulations queried (not including AGE and SEX)

13. Feedback from the WG
First comments/reactions about these preliminary results
Which type of statistical analysis could be useful to derive quantitative measures about the relevance of the different topics and tabulations?

14. Thanks for your attention!