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 sequence data (from different organisms) are not sufficient for this purpose, several alternative approaches were suggested as compromises between using multigenes and using multiorganisms (e.g., Wray et al. 1996; Doolittle et al. 1996; Nikoh et al. 1997).
Category: