Accuracy and reliability

Overall accuracy

All Universities and other Institutions approved to offer PhD-educations reports data. The statistics therefore provide an accurate picture of PhD students and awarded PhD degrees at Danish institutions. It should be noted, however, that older doctoral degrees (e.g. dr.med. and dr.phil.), which are not PhD programmes, are not included.

Sampling error

Not relevant for these statistics.

Non-sampling error

Coverage: Concerning number of PhD-students the statistics covers the target population. Concerning number of PhD-graduates please note that the statistics covers degrees taken at Danish Universities, while degrees taken at Universities abroad by people of Danish or foreign origin in most cases are not included.

*Measurement errors: With regard to the core variables, the number of PhD students and the number of awarded PhD degrees, the quality is expected to be good and no significant measurement errors are considered to occur, as the error-checking procedures are very extensive. With regard to information on the main field of study, the quality is also assessed as good, but measurement errors may occur, as the information is based on the individual’s institutional affiliation at the university. Changes in faculty structures and departmental organisation may therefore affect the precision of the information on the main field of study.

The students and the information on the main variables are checked very carefully, and on the whole only few cases of "missing data" does not.

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

Accuracy: In general the accuracy is very high. All universities and other Institutions approved to offer PhD-educations reports data.

Reliability: Concerning number of PhD-students the statistics covers the target population. Concerning number of PhD-graduates please note that the statistics covers degrees taken at Danish Universities, while degrees taken by people living in Denmark at Universities abroad in many cases are not included.

Concerning the central units: PhD-students and PhD-graduates the quality is considered as being very good as the corrections-procedures are very thoroughly. Concerning the information on Main field of the research project the quality is expected to be good, but the information is based on the individual’s institutional affiliation at the university. Changes in faculty structures and departmental organisation may therefore affect the precision of the information on the main field of study.

The students and the information on the main variables are checked very carefully, and on the whole "missing data" does not occur.

Comparability: Comparability over time for the main variables is good. Though there has been institutional changes for the main fields, which create a minor data breache in 2012. This is due to changes in the Faculty and Institute structure, some of the big universities has carries out. Some recoding has been done to ensure that the variable main field are consistent up till 2011. From 2012 changes could not be avoided especially for Agriculture and Veterinary science.

Comparability to international statistics on number of PhD-students are considered to be very good. Concerning international comparability of the education level of the population, countries using surveys have the possibility of including persons, who have obtained the PhD-degree abroad. These group is only partly included in the Danish statistics on attained education used for international comparison. Since the statistics on PhD-degrees for this purpose is supplemented with information on education taken abroad for persons immigrated in the years up till 2006.

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

It is possible for the universities to sent supplementary information referring to former reference periods. The corrections concerning the previous year will be included in the next publication. Other corrections will be included at the next big data revision.