adequate statistical power

adequate statistical power

After completing this week’s assigned readings, discuss one of the following questions:

1. What things can a researcher do to try to increase the magnitude of the d effect size? Suppose that you can increase the d effect size while holding group sizes n1 and n2 constant. How will an increase in d influence the magnitude of t ?
2. Several factors influence statistical power for a one-sample t test. How does statistical power change (increase or decrease) for each of the following changes?
   • When d (effect size) increases.
   • When N (sample size) increases.
   • When the alpha level is made smaller.
   • Explain your answer. For example, if we know ahead of time that the effect size d is very small, what does this tell us about the N we will need in order to have adequate statistical power? (We assume that all other terms included in the r ratio remain the same.)