In a research study, the most difficult factor to specify in any determination of power is the size of the true effect.

Question

Quizplus · Accepted Answer

This is because the size of the true effect is often unknown and can only be estimated based on previous research or expert opinion. This uncertainty can make it challenging to accurately calculate the sample size necessary to detect a significant effect with a certain level of power.

In a Research Study, the Most Difficult Factor to Specify