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:Accordingly, time-to-contact measures may yield information about dynamic stability in balance (Patton et al. 1999; Van Wegen et al. 2001; 2002; Haibach et al. 2007) and serve as a ‘‘detector/predictor’’ of future instability.
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