In 2005, Stanford epidemiologist John Ioannidis published the provocatively titled paper “Why most published research findings are false” (Ioannidis, PLoS Med 2005, 2:e12), that has since become a foundational piece of metascience. Among other things, he stated: The smaller the study sample conducted in a scientific field, the less likely the research findings are to…

# Tag: NHST

## Fisher’s exact test

Fisher’s exact test is used to compare counts and proportions between groups when small samples of nominal variables are available. It assumes that the individual observations are independent, and that the row and column totals are fixed, or “conditioned.” An example would be putting 12 female hermit crabs and 9 male hermit crabs in an…

## Does the p-value overestimate the strength of evidence?

Thom Baguley points to the standardized or minimum LR (p381) to answer this question. The minimum LR represents a worst case scenario for the null in that it compares the LR for against the MLE of the observed data, i.e. the most likely (strongest) possible hypothesis supported by the data, and is defined as …

## Classical statistical inference and its discontents

“Classical” statistical inference in medicine is usually synonymous with frequentist inference, the central element of which is the null hypothesis significance testing (NHST). Even though that was not its original intent, NHST is in practice used to evaluate the evidence for or against a hypothesis, due to confusion in mixing Fisher’s approach with that of…