1. Technology and procedures for correction of errors and discrepancies of data
Workshop on Experiences with Data Management to Improve Land Administration In ECE Countries
Sofia, Bulgaria, 23 – 24 April 2009
Jaroslav Bačina
Czech Office for Surveying, Mapping and Cadastre

2. Data quality History of data correction in the Czech Republic
Digitalization of cadastral data – not all the applications adhered to standards of recording data
Harmonizing of data in local databases with the central database
The implementation of a new information system for the cadastre of real estates in 2001 (ISCRE)
Data analysis and data corrections
Czech Office for Surveying, Mapping and Cadastre

3. Data quality Data correction is determined
by the Cadastral Act No. 344/1992:
Cadastral officies shall correct any errors in the register on their own initiative or following a written petition submited by the owner.
Errors resulted from the renewal and maintenance of the cadastre, inaccuracies during measurements and in depicting the bounderies in the cadastral maps.
Czech Office for Surveying, Mapping and Cadastre

4. Data quality
The errors in records of legal rights, parcel numbers can be corrected according to the deeds submitted to cadastral office for registration.
The errors in boundary determination can be corrected according to survey documentation along with a written declaration of the owners of the neighbouring parcels.
Other discrepancies of the data are corrected according to adopted standards or the correct data can be taken from some other state registers.
Czech Office for Surveying, Mapping and Cadastre

5. Data quality
The Czech Office for Surveying, Mapping and Cadastre has issued:
Instruction No. 2055/ on data quality improvements,
Instruction No. 3051/ on standardizing the name and address data of the owners.
The Czech Government has issued
the Decree No. 111/2001 on matching and acceptance of the cadastral data and the data of the Population Register.
Czech Office for Surveying, Mapping and Cadastre

6. Data quality A huge data correction process was launched in 2001 to
Adjust the data to new data models in ISCRE - the new business rules were not applicable to all historical transactions and records
Standardize the data
Correct the spelling errors
Remove duplication in the records
Czech Office for Surveying, Mapping and Cadastre

7. Data quality Working group for data control Established in 2008
Data analysis
Proposals for software updates
Guidlines and instructions – methodology
Fixing a term for data corrections
Czech Office for Surveying, Mapping and Cadastre

8. Data quality Team of contact persons
Discrepances of the same data recorded in several workplaces
Data is checked with the deeds
1 contact person for each cadastral workplace
1 workplace is determined as a leading one in each instance
Communication by software application or by s
Czech Office for Surveying, Mapping and Cadastre

9. Data quality Sets of error records
Created by the Central Database Department
Accessible by cadastral workplaces via Internet
Data designed in structured fields
Updated version of the sets of error records
Czech Office for Surveying, Mapping and Cadastre

10. Data quality
Czech Office for Surveying, Mapping and Cadastre

11. Data quality Database scripts as an automated tool for data correction
Created by the Central Database Department
Response to control analysis or legislative changes
3 – 4 scripts per year
All error data is corrected at the same moment according to rules
Czech Office for Surveying, Mapping and Cadastre

12. Data quality Data error prevention Data standardization
Use of code lists
Integrity constraints
Control digit test
Input controls
Administrative measures
Czech Office for Surveying, Mapping and Cadastre

13. Thank you for your attention.
Czech Office for Surveying, Mapping and Cadastre