- Correlation does not imply causation!
- A p-value is the probability of the data, not the probability of a theory.
- Absence of evidence is not evidence of absence!
- Essentially, all models are wrong, but some are useful. (G. Box)
- Prussian military commander Helmuth van Moltke wrote in 1880, “No plan of operations reaches with any certainty beyond the first encounter with the enemy's main force.”
- Statistical tests should be used with “discretion and understanding, and not as instruments which themselves give the final verdict.” (Neyman & Pearson, 1928)
- Statistical power is the probability of observing a statistically significant result! It is a function of the effect size, the alpha level and the sample size.
- Extraordinary claims require extraordinary evidence. (Laplace, 1812)
- Effects can be statistically significant, but practically insignificant.
- Everything we eat both causes and prevents cancer (publication bias, p-value threshold problem)
