The magnitude of the fit statistic depends on how many items were shown in each set. If four items are shown in each set, then any random set of scores should be able to predict respondents' answers correctly with 25% likelihood (fit statistic=.25). If two items are shown per set (paired comparison approach), then the expected likelihood given random data is 50% (fit statistic=.5). Thus we can generalize that the fit statistic should be at a minimum 1/c, where c is the number of items displayed per set.
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