Honorary authorship and Ghost authorship
Two other phenomena with respect to authorship are the following.
Sometimes researchers are listed as author although they did not make a significant contribution to the work. In this case one speaks of honorary authorship (Wislar, Flanagin, Fontanarosa, & Deangelis, 2011) or gift authorship (COPE, 2003). Sometimes, for instance, heads of departments are listed as an author although they are not familiar with the content of the article.
The opposite sometimes occurs as well, that someone contributes to an article but that that person’s involvement is not acknowledged. In this case one deals with a ghost writer (COPE, 2003). This for instance can occur in collaborations with private enterprises where a professional writer is hired to transform the research results in an article and use a wording that might be beneficiary for the private company involved in the research. Not including the ghost writer as an author then clouds the participation of an external company.