Statistics – Was the Finding Significant?

Abstract To appreciate how medical research works it is necessary to understand the vital role played by statistical analysis. How one can determine if a person is truly a psychic is used to introduce the concept of statistical significance — the criterion that determines whether an experimenter can claim he or she has found a treatment difference. The explanation relies on simple coin tosses and the creation of a testing standard to determine if a person claiming psychic powers should be believed. The role of the confidence interval, which is essentially the “margin of error” that is faithfully included in political poll results, is incorporated into the explanation as well. The need to establish a null hypotheses and appreciation for the types of errors that come from statistical analyses are also covered. In addition, the chapter presents issues that must be addressed to judge whether any treatment differences found are truly meaningful. Included are (1) the assumptions researcher must make to determine the number of subjects they need for a trial and (2) the role of clinical relevance.