“…One category has mainly concentrated on investigating the different impacts of the relevant and irrelevant feedback documents or how to reduce the negative impact of the irrelevant documents (for instance, Mbarek et al (2017); Raman, Udupa, Bhattacharyya, & Bhole, 2010;Singhal, Mitra, & Buckley, 1997;Wang, Fang, & Zhai, 2008;Basile, Caputo, & Semeraro, 2011). For example, Raman et al (2010) utilized irrelevant feedback documents to extract specific expansion terms from top-ranked documents and showed that good expansion terms are those that discriminate the top-ranked documents. The other category involves proposed methods of improving QE processing (for instance, Carpineto et al, 2001;Collins-Thompson, 2009;Greenberg, 2001b;Bai, Song, Bruza, Nie, & Cao, 2005).…”