**Must-Read: Felix Schönbrodt**: 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

http://www.nicebread.de/whats-the-probability-that-a-significant-p-value-indicates-a-true-effect/

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