Background Consider these four conditions: There is no reliable prior information about an effect and an uninformative prior is used in the Bayesian analysis There is only one look at the data The look was pre-planned and not data-dependent A one-sided assessment is of interest, so that one-tailed p-values and Bayesian posterior probabilities are used, where is the effect parameter of interest (e.g., difference in means, log effect ratio) and means “conditional on” or “given”. One-Sid...| Statistical Thinking
Background Consider the problem of comparing two treatments by doing squential analyses by avoiding putting too much faith into a fixed sample size design. As shown here the lowest expected sample size will result from looking at the developing data as often as possible in a Bayesian design. The Bayesian approach computes probabilities about unknowns, e.g., the treatment effect, and one can update the current evidence base as often as desired, knowing that the current information has made pre...| Statistical Thinking