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:Internal consistency for the PIWSUR total score were reported to be excellent by (Burns et al. 1996) (Cronbach’s alpha = 0.92), and for the subscales was fair to good with alphas ranging from 0.77 to 0.88.
Category: