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:As in past research (McBride et al. 2003), responses for girls’ menarche were coded (1 = no; 4 = yes) to create a scale comparable to other items and a mean score across all five items was computed for both girls, α=0.
Category: