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:, 2013; Tucker, 2012), but other interactive technologies or materials such as textbooks and handouts are also mentioned (McLaughlin et al., 2014; Prober & Khan, 2013; Strayer, 2012).
Category: