Repeated failures of entire body of scientific research (many replicated studies etc.) to disprove the null hypothesis are accepted provisionally as a basis for concluding that the groups, in fact, do not differ. Thus scientific research CAN document and show and this is why this wording is used by several most reliable sources in the topic. Please stop immediately discredit and desinterprest reliable sources as you tried by claiming in edit status that it is not scientific research. This is unacceptable!