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:Variability in the data, in terms of variability of each behavior relative to the variability of other behaviors, and the total variance of the whole composition, is described in Appendix 3 through a variation matrix [11, 16] within each domain.
Category: