Geoaudit Ltd1 3 rd Party Quality Evaluation Experience with the finnish TDB
Geoaudit Ltd2 TDB Quality Model 1 st edition 1993, 2 nd published 1995 The basic idea: 100% is not possible Test work to define goals Acceptable quality limits (AQL) for completeness and correctness AQL 1, 4, 15 and none Accuracy 3 m, 5m, 15 m … (95%)
Geoaudit Ltd3 TDB Quality Model Internal quality tests in 13 District Survey Offices sampling according to ISO rectangular 1 sq km samples described in Annex F of ISO (QEP) External quality tests accuracy control logical consistency control comparison between the 13 offices
Geoaudit Ltd4 Why a 3 rd party? Independent Quality Evaluation Stratecig choice of MAF Customer feedback Internal market –NLS Central Administration acting as a client –Survey Office in the role of a producer Quality in key role in the result matrix –matrix of cost, schedule, quality etc. in the best case resulting minor bonuses for employees
Geoaudit Ltd5 Previously in society… Money is invented squirrel hide in Finland
Geoaudit Ltd6 Previously in society… Money is invented Squirrel hide in Finland More money -> accountants needed More acountants -> Auditors needed (spatial) Information is invented…
Geoaudit Ltd7 Geoaudit Oy est 60% of turnover from NLS Metadata implementation & INSPIRE indicate growth potential Quality evaluation is expensive What is the benefit for a producer to include reliable data quality results in his metadata?
Geoaudit Ltd8 Data Quality Elements Complete, consistent, accurate, timely, correct Is this the correct order? Example of the balance between completeness and accuracy:
Geoaudit Ltd9 Completeness vs. Accuracy TDB accuracy report 2005 Mean value of positional uncertainties excluding outliers ~1.50 m Not normal distribution Outliers indicate that some features are surveyed in the field GOOD IF YOU VALUATE COMPLETENESS OVER ACCURACY!
Geoaudit Ltd10 Thank you for your interest!