The majority of the scientific papers include keywords besides the obligatory title and abstract. The use of keywords is not just for the description of content, but it is a viral part of the scientific paper which is later used for information retrieval function. The aim of this paper is to present comparison of author suggested keywords in scientific papers of Faculty of Electrical Engineering and Computing (FER), IEEE terms and user tags in academic social network Mendeley. This paper will examine the scientific papers represented in IEEE Journals and Magazines indexed in the IEEE/IET Electronic Library reviewing the overlap between author keywords and IEEE terms from a controlled vocabulary (IEEE thesaurus) and user tags in Mendeley. The results showed no significant use of controlled vocabulary and social tags, which leads to the conclusion that the authors are not aware of the importance of controlled keywords.