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:Table 4: Number of function evaluations reported for the particle swarm optimization (PSO) [7] and contact interactions (CI) [8] methods and calculated for our AGAHP implementation for protein chains 27 amino acids in length.
Category: