I have a few rules that I aim to use when I run studies. By considering what it looks like when these rules are inverted, they also may help guide you in thinking about which studies are not reliable. (1) Don't use a net with big holes to catch a small fish That means you should use a large enough sample size (e.g., number of study participants) to reliably detect whatever effects you're looking for! (2) Don't use calculus to help you assemble IKEA furniture  That means...