What’s “wrong” with null hypothesis significance testing?
Three main criticisms against NHST as a dominant method of scientific “proof” have been voiced for the past 80 years, ever since Sir Ronald Fisher introduced the concept and laid the basis for structural models and computations in 1925. • The first criticism is that by focusing on “proof by contradiction,” it doesn’t really tell us what we want to know, yet “we so much want to know what we want to know that, out of desperation, we nevertheless believe that it does.”5 As Cohen and others have written, “What we want to know is, ‘Given these data, what is the probability that Ho [the null hypothesis] is true?’ But as most of us know, what [NHST] tells us is, ‘Given that Ho is true, what is the probability of these (or more extreme) data?’ (ibid).” These two statements are not the same although they sound very similar. The scientific inference we wish to make is inductive: it goes from the sample to the population and concerns the viability of our alternative or research hypothesis. Null h
