“…Once Web 2.0 and social media sites became popular, they attracted the research interest of many scholars and information professionals. Some studies discussed social tags with classic topics, such as information organization (Golub et al , 2014; Tennis, 2006; Wetzker et al , 2008; Yi and Chan, 2009) and information retrieval (Carman et al , 2008; DeZelar-Tiedman, 2011; Gelernter, 2007; Guerra and LaPlante, 2011; Li et al , 2008; Ruiz and Chin, 2010); some investigated the types of tags (Golder and Huberman, 2006; Gupta et al , 2010; Thomas et al , 2009); some focused on tagging behaviour and the motivation behind it; some studies paid attention to the relationship between book tags and controlled vocabularies, such as subject headings or Dublin Core (Catarino and Baptista, 2010), and the application of social tags in library service (DeZelar-Tiedman, 2011; Gelernter, 2007; Kakali and Papatheodorou, 2010; Lu et al , 2010; Peters, 2009; Thomas et al , 2009).…”