Evaluating the Null Hypothesis
So, if the null hypothesis is the best explanation, then...
If the alternative is the best explanation, then...
Statistically Evaluating the Null Hypothesis
Compute the probability that the treatment effect is due to chance alone
Step 2: If the probability that the treatment effect is due to chance is low enough...
Step 3: If the probability that the treatment effect is too high...
Errors in Science
True state of affairs (reality)
|Correct decision||Type II
-limited to alpha
Threats to internal validity
Diffusion/Imitation of treatments