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:8 To validate the quality of our categorization, the next section discusses series of experiments that compare the performance of the vector space categorizati on approach with one of the top classifiers, Naïve-Bayes (Friedman et al., 1997).
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