This special issue of the Scandinavian Journal of Public Health is devoted to articles on the Copenhagen Psychosocial Questionnaire (COPSOQ). I have been asked to participate with a personal contribution and have been given the freedom to write whatever I find appropriate.My main message in this article is that a questionnaire is not just a questionnaire. A questionnaire, such as COPSOQ, is a tool for creating theoretical insight, an eye opener for employees and employers, a way to create a new language, a bridge for building long lasting ties between researchers and workplaces, a way to give legitimacy to the field of psychosocial factors at work, an instrument for creating new personal and professional friendships, and -last but not least -a tool for improvement of the working conditions for thousands of employees and for increasing the productivity of the companies.I cannot cover all these aspects in detail but I will touch upon most of them in the following.
The aims of COPSOQAbout 15 years ago Vilhelm Borg and I founded the psychosocial research group at the National Institute of Occupational Health in Denmark. Before this time the institute had given priority to physical, chemical, and ergonomic factors at work. After a short while we were approached by several work environment professionals who had serious problems in connection with the assessment of psychosocial factors at the workplace. A large number of private consultants and firms offered many different tools and questionnaires but the quality seemed to be low, there were no national data, and -above all -there were no criteria for choosing one instrument over another. The professionals asked for national standards and guidelines, and -if possible -a national instrument.We decided to take up this challenge. During our discussions the idea of the ''Three-level concept'' quickly emerged: A long questionnaire for the researchers, a medium size for the professional work environment experts (occupational health services, labour inspection, private consultants, organizations, big companies), and a short version for the smaller companies and workplaces. As a natural consequence of this, the following goals of the Three-level concepts were formulated [1]:To develop valid and relevant instruments for the assessment of psychosocial factors at work To make national and international comparisons possible To improve evaluations of interventions To facilitate surveillance and benchmarking To improve the communication between workplaces, work environment professionals, and researchers To make it easier for the users to understand difficult concepts and theories It is of course up to others to evaluate to what degree we have reached these goals, but I can honestly say that for the founding group the success of the COPSOQ concept has been much greater than we had ever imagined. I believe that the articles in this special issue demonstrate this point.Going beyond ''the two models'' From the beginning it was clear to us that the questionnaire should be theory based bu...