Must-Read: : The False Discovery Rate (FDR) and the Positive Predictive Value (PPV): “To answer the question ‘What’s the probability that a significant p-value indicates a true effect?’…
…we are interested in a conditional probability Prob(effect is real | p-value is significant). Inspired by Colquhoun (2014)… a tree-diagram….
[For a population in which 30% of investigated effects are real and statistical power is 35%,] the false discovery rate (FDR): 35 of (35+105) = 140 significant p-values actually come from a null effect… much more than… 5%…. Together with Michael Zehetleitner I developed an interactive app that computes and visualizes these numbers…. Run the App