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:Following Oksanen (2001), we have treated each floodplain channel and floodplain floodout habitat as independent, as the hypotheses being tested relate to indicators that are responsive within small-scale (hydro-geomorphic unit) environmental gradients (see also O’Neill et al., 1986).
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