A researcher has already written a study proposal and performed a power analysis, which indicates that the sample size will have to be at least 36, in order to avoid Type II error. The researcher then decides to set the level of significance at p

Question

A researcher has already written a study proposal and performed a power analysis, which indicates that the sample size will have to be at least 36, in order to avoid Type II error. The researcher then decides to set the level of significance at p < 0.01 rather than p < 0.05 but wants to maintain power at 0.80. What will the researcher have to do in order to maintain sufficient power?

Quizplus · Accepted Answer

To maintain sufficient power (the probability of correctly rejecting a false null hypothesis) at a lower significance level (p < 0.01 instead of p < 0.05), the researcher will need to increase the sample size. A lower significance level means the criteria for rejecting the null hypothesis are stricter, which can reduce power if other factors remain constant. Increasing the sample size compensates for this by improving the study's ability to detect an effect if there is one.

A Researcher Has Already Written a Study Proposal and Performed