In statistics class, we learnt that alpha = type 1 error rate, and type 1 error rate is the probability of wrongly rejecting our null hypothesis when it is true. It is equal to the red area of the following figure.
I counted for you, there are 25 ANOVAs and 250 post hoc independent sample t-tests there... And as indicated by the researchers, they consider the p-value 0.05 to be significant. And if the researchers had used Bonferroni correction, I am afraid nothing would have been considered statistically significant...
Therefore, I want to know can I (or should I) calculate the overall Type 1 Error rate for a STUDY, but not just for a single test? Also, I want to know whether other methods to control for Type 1 Error rate exist.
Thank you very much.