Testing hypotheses suggested by the data - Wikipedia, the free encyclopedia
en.wikipedia.org/wiki/Testing_hypotheses_suggested_by_the_dataHypotheses suggested by the data, if tested using the data set that suggested them, are likely to be accepted even when they are not true. This is because circular reasoning (double dipping) would be involved: something seems true in the limited data set, therefore we hypothesize that it is true in general, therefore we (wrongly) test it on the same limited data set, which seems to confirm that it is true.