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:The OCD individuals were diagnosed with the Structured Clinical Interview for Diagnostic and Statistical Manual of Mental Disorders (SCID-I) (First et al. 1996) and OCD symptom severity was assessed using the “The Yale-Brown Obsessive Compulsive Scale” (YBOCS) (Goodman et al. 1989).
Category: