Measuring the Strength of the Evidence

David Trafimow
2018 Biomedical Journal of Scientific & Technical Research  
Many proponents of p-values assert that they measure the strength of the evidence with respect to a hypothesis. Many proponents of Bayes Factors assert that they measure the relative strength of the evidence with respect to competing hypotheses. From a philosophical perspective, both assertions are problematic because the strength of the evidence depends on auxiliary assumptions, whose worth is not quantifiable by p-values or Bayes Factors. In addition, from a measurement perspective, p-values
more » ... nd Bayes Factors fail to fulfill a basic measurement criterion for validity. For both classes of reasons, p-values and Bayes Factors do not validly measure the strength of the evidence. Nor does coming at auxiliary assumptions from a verificationist position help much. As the cliché has it, empirical victories do not prove theories to be true because of the logical fallacy of affirming the consequent. For a chemistry example, phlogiston theory made some correct predictions, but the predictions worked for reasons
doi:10.26717/bjstr.2018.06.001384 fatcat:3qrvh72orza5ta3ehdfq265hnu