Evaluate the collective function of references cited together in a given text segment.
Classify their combined role into one of the following categories: 'method', 'background', or 'result'.

Text:…2009), compare the quality of association measures through mean average precision (Evert and Krenn 2005), compare different methods (Pearce 2002; Ramisch et al. 2008a), and measure the impact of acquired MWEs on NLP applications (Finlayson and Kulkarni 2011; Xu et al. 2010; Carpuat and Diab 2010).
Category: