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:Stimuli were 12 3 12 arrays presented in the centre of the white screen, with each array position occupied by either a blue or red alien cartoon character (‘‘greeblie’’) measuring approximately 8 mm
wide and 9 mm high (see Figure 3, Lie & Alsop, 2009).
Category: