The significance level in a one-tailed test is often set at 1%, 5%, or 10% to measure the probability of rejecting a true null hypothesis. A one-tailed test is chosen when it is unnecessary to ...

At times we wish to examine statistical evidence, and determine whether it supports or contradicts a claim that has been made (or that we might wish to make) concerning the entire population. This is ...

It may be common knowledge that p < .05 indicates statistical significance. Psychology students (and others) are often taught that p < .05 means the probability (p) of rejecting the null hypothesis ...

Hypothesis testing problems in which the null hypothesis is simple, the parameter space is finite dimensional and the supports of the probability measures are independent of the parameter are ...

Jacob Cohen (1923 - 1998) was a pioneer of psychological statistics. He taught us about effect sizes, power analysis, and multivariate regression, among many other things. I have always admired his ...

Technologies of measuring millions of quantities at once have been rapidly developed and used in biological and biomedical research and other fields in the past decade. Yet a key issue remains ...