Practice quiz: Power and sample size

4 questions. Pick an answer to see if it is right. You can try as many times as you like. These are for practice: the final test has different questions.

1. 1.Statistical power is...

   the chance the null hypothesis is truethe chance of detecting an effect if it really existsthe size of the effectthe p-value
2. 2.When a low-powered study finds a significant effect, the effect is often...

   underestimatedexaggeratedexactly rightzero
3. 3.Roughly how many people per group to detect d = 0.5 at α = 0.05 with 80% power?

   About 10About 64About 1,000About 5
4. 4.Patients start a new remedy when their pain is at its worst, and most feel better a week later. Before crediting the remedy, you should consider...

   regression to the meanSimpson's paradoxthe medianBonferroni correction