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:We adopted the Th.o.m.a.s., an interview aimed at an articulated exploration of ToM (Bosco et al., 2009a; Castellino et al., 2011) and an advanced ToM test, namely the Strange Stories test (Happé et al., 1999), aiming to provide a complete assessment of such complex cognitive ability.
Category: