# What causes low power on hypothesis tests?

I've been doing hypothesis tests to compare two proportions in a product. Although the sample size is supposed to be more than enough based on the population and $$\alpha$$ (type I error), the power of the experiment ($$\beta$$, type II error) is very low. Why is that?

• Usual culprits: sample size, difference in means, standard deviations of means, $\alpha$. – user2974951 Feb 19 '19 at 9:24