Accuracy and reliability

Overall accuracy

The overall accuracy and reliability of the results of the members' activities of the sports organizations, international medals, rank and attendance is considered to be high, as it is build on register information from central and authoritative sources. For an assessment of the overall accuracy and reliability of the results regarding the Danish sports and sports habits, refer to the original reports from the Sports Analysis Institute.

The medal statistics are based on the DIF's medal database., Data regarding the members' activities are provided on the basis of databases from the Central Association Register. The numbers of spectator deliver from the unions databases. The ranking tables are based on special extracts from a relative medal table that compares international sports performance prepared by Gracenote - A Nielsen Company.

In the use of registerbased data there can be uncertainty associated with error registration, time shifts as well as missing alerts. Error registrations could lead to shifts in data as well as time series. Time delays are based on delays in the delivery of data, which can either exceed or underestimate statistics. Failure to report will underestimate the statistics in the form of for example missing member information and registrations of new spectators.

There are some discrepancies in the membership for 2019 compared to 2018, which relates to the tables IDRAKT01 and IDRAKT02. This is due to the fact that it is the local business sports associations that register how many people exercise at work in their local areas. It is a practice that is underway, with some of the local corporate sports associations registering exercise at the workplace to a greater extent than before. This applies, for example, in the municipality of Lemvig. In addition, the relocation of members between municipalities can be a cause of large member fluctuations, which is the case for Brønderslev and Albertslund in 2019. This is due to the fact that larger national associations during corporate sports are registered under the municipalities where the companies are headquartered.

Due to COVID-19 there will be a decrease in the number of matches played, the number of attendances and the average number of attendances per match season 19/20 in the table IDRTIL01. The 19/20 season was cancelled for The Handball League, the Basketball League and the Super Ice League, which is why the number of matches and thus the total number of attendances is significantly lower than in previous years. For the Supericeleague, 8 matches were played without attendances, which also contributes to the average number of attendances falling. This is also the case for the Super League as well as the 1st Division in football, where the last part of the season was played with limited spectators or for empty stadiums. In general, in the 19/20 season had fewer national matches, which is due to the fact that, the planned matches during COVID-19 were also canceled. Due to the new tournament structure, the 3rd division is included in men's football from the 2021/22 season, because the 2nd division has been split up into two independent divisions.

Sampling error

Assessment of sampling errors of results regarding the Danish sports and sports habits, refer to the original reports from the Sports Analysis Institute. The Danes' exercise and sports habits 2016 is an independent study conducted by the Sports Analysis Institute. The data collection was carried out by Rambøll in the period from January to March 2016 by sending out invitations to an online questionnaire. The invitations to the survey have been sent out to a random CPR-based representative sample. 6,500 children and 11,000 adult Danes were sent the invitation per. letter, of which 3,221 children and 3,914 adults answered the questionnaire. The response rates were thus 49.6 per cent. for children and 35.6 per cent. for adults. The response rate for adults is thus at the low end and somewhat lower than the previous surveys from 2011 and 2007, where the response rates were 43.6 and 47 per cent, respectively. The 2020 questionnaire resulted in 6,917 answers for adults (16 years +) and 4,379 answers for children (7-15 years) corresponding to response rates of 34 percent, and 49 percent.

The stat table IDRKVU01 is based on the Cultural Habits Survey, which is why reference is made to its documentation for the precision of the sample. An important source of uncertainty in this study is the sample uncertainty. Measured by key indicators, this source of uncertainty is less than one percent. There are answers from respectively 55 and 48 percent of those surveyed in the first two quarters of the survey, which is a further source of uncertainty for the study. It is also the case that certain types of groups more often do not respond and it affects the representativeness of the study. However, this is largely addressed through the enumeration and use of register-based assistance information. Although the assistance information tackles a lot of bias, it cannot be ruled out that there is systematic bias in the cultural consumption study. However, this will only affect the level and not the development.

Non-sampling error

Activity, association and member information is based on data from the Central Association Register and thus covers the organized association sports. Sport in a more private matter is therefore not covered by this data. This could be, for example, private yoga centers, fitness centers or match clubs. The activity in these must therefore be considered to be underestimated. However, the study of sports habits from the Sports Analysis Institute captures some of this activity due to a different question frame.

Register information about sports activities is based on reports from the individual sports associations, and there may therefore be variations in registration practices. This also relates to reported data for the rank tables from Gracenote as well as the medal statistics which are based on the Danish Sports Confederation's medal overview.

In such register-based data, there may be uncertainty associated with erroneous registration and time shifts. Error registrations could lead to shifts in data and time series. This could, for example, be a sports association that has incorrectly registered the number of members, which will over or underestimate the number of members or incorrectly reported spectator numbers for a given association. Delayed reporting of data could also lead to time delays, which will contribute to the statistics for sports activities in a given year being over or underestimated.

Dropouts in the form of missing reports will downgrade the statistics in the form of, for example, missing member information from a sports association. In the attendance statistics, four single matches over four seasons (Woman2009/10, Woman2011/12, Men2015/16, Woman2016/17) for men and women national teams in handball, there is no attendances. The correlation between the number of matches and the number of attendances for these individual seasons may therefore be slightly different. Attendances per. match in the above seasons are calculated without the individual mentioned matches. In a single match for the basketball national team season 2007/08 there is no attendance. The correlation between the number of matches and the number of attendances for this individual season may therefore be slightly different. Attendances per. match in the above mentioned season is calculated without the individual mentioned match.

Due to COVID-19 there will be a decrease in the number of matches played and attendances. Data comes from the unions' reports, which it must considered to be of high quality.

In relation to the fact that we measure sports, it is assumed that the formalized tables are an indication of the total practice of sports in Denmark. The delimitation of the statistics for sports / tournaments and for spectators is as follows:

• The sport must be practiced by professional athletes who are basically on contract in a club.
• The sport must be categorized on the basis of a professional league and structure, where the number of matches / events as well as the number of spectators over a time series is recordable from season to season.
• Tournaments with several events during one on the same event are not included in the statistics in question.
• The sporting events must take place in Denmark.
• The sporting events must have a minimum attendance of 150 people.

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 key and well-known authoritative sources, and the quality of the results regarding the member activities of the sports organizations, international medals and attendance is considered high as it builds on register information published by organizations who maintain these statistics. A quality assessment of the results regarding Danish sports and sports habits, refer to the original reports from the Sports Analysis Institute. There is not made any real quality assessment of this statistics.

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

Only final figures are published.