Accuracy and reliability

Overall accuracy

In terms of the overall statistical objectives, the statistics are accurate. This includes, number of vessels and the total tonnage, as accurate registrations in the ship register have fiscal significance for ship owners.

Uncertainty regarding vessels use and age are minimal and does not impact the overall assessment of the statistics.

Sampling error

Not relevant for the statistics.

Non-sampling error

Since certain ship types can serve multiple purposes and their use may change over time, there is some uncertainty regarding their usage. However, the ship register is updated when ships undergo definitive conversions for entirely new purposes.

Quality management

Statistics Denmark follows the recommendations on organisation and management of quality given in the Code of Practice for European Statistics (CoP) and the implementation guidelines given in the Quality Assurance Framework of the European Statistical System (QAF). A Working Group on Quality and a central quality assurance function have been established to continuously carry through control of products and processes.

Quality assurance

Statistics Denmark follows the principles in the Code of Practice for European Statistics (CoP) and uses the Quality Assurance Framework of the European Statistical System (QAF) for the implementation of the principles. This involves continuous decentralized and central control of products and processes based on documentation following international standards. The central quality assurance function reports to the Working Group on Quality. Reports include suggestions for improvement that are assessed, decided and subsequently implemented.

Quality assessment

The statistics are based on an administrative register of Danish-registered ships. The information from the register fully encompasses the scope of the statistics.

No preliminary figures are published.

Overall, the statistics are considered to be of good quality, as they are based on an administrative register, where the number and size of the ships, in particular, are regarded as information of very high quality.

Data revision - policy

Statistics Denmark revises published figures in accordance with the Revision Policy for Statistics Denmark. The common procedures and principles of the Revision Policy are for some statistics supplemented by a specific revision practice.

Data revision practice

Preliminary figures are not being produced.