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 assessed opposition to Arab immigration by
asking participants to assign a limited number of immigrant visas to various groups (e.g., East Asians, Arabs, Eastern Europeans), and then taking the reverse-scored proportion of visas assigned to Arabs (Kteily et al., 2015).
Category: