Accuracy and reliability

Overall accuracy

There are many different types of vocational education, ways to take an vocational education and types of institutions. This means that the risk of errors in the data is increased since the complexity of the vocational education system increases the possibility of errors in the entries in the administrative systems. Moreover, there are different administrative practices between the schools that create discrepancies. Finally, the schools' administrative systems use a different format than the one used in the Student Register. That means that there is a risk that errors arise in the treatment of data at either the National Agency of IT and Learning or Statistics Denmark. Especially for specific groups and educations there is a uncertainty in the statistics. The uncertainty is especially with regards to the latest year, since many errors are corrected by the institutions in the following year.

Sampling error

Not relevant for these statistics, since it is a total counting.

Non-sampling error

Coverage errors can be persons enrolled on a vocational education that is not registered in the statistics. Measurement errors can occur due to the many different parts and ways to obtain a vocational education. Calculation errors can happen when converting to the format used for production of the statistics. When dates overlap for a student, the student usually is registered as finished on the first education on the date where he is registered to begin on the next education.

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 strength of the statistics are that data are collected from the institutions' administrative registers, which the institutions use for the administrations of their students. There are however certain challenges with regards to vocational education which makes the quality of the data a bit more uncertain than with other types of education.

Vocational education is complicated. The student needs to be placed on a basic or main course and on a so-called "education road", which shows whether the student begins their education at school or in practical training, which means more possible sources of errors.

In addition, there are often large fluctuations from year to year in this field. That makes it harder to find eventual errors, since large fluctuations not necessarily is an error.

All in all, the data quality in the vocational education field is therefore more uncertain that in other educational fields.

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

The institutions have the possibility of updating backwards in time when reporting data. When that happens, data from previous years are revised.