When calculating power, how does a researcher know what estimate to use for the effect size?
A) The researcher should always assume there will be a large effect size
B) The researcher should always assume there will be a medium effect size
C) The researcher should investigate past studies in the same content area to estimate the effect size
D) There is no single way to estimate effect size

Question

Quizplus · Accepted Answer

The best way to estimate effect size when calculating power is to investigate past studies in the same content area. This allows the researcher to get an idea of what effect sizes are typically found in that area of research and to use that estimate for their own study. It is important to choose an effect size that is realistic and based on previous research, rather than assuming a large or medium effect size without any evidence. Therefore, option A and B are incorrect. Option D is also incorrect as there are established methods for estimating effect size based on previous research.

When Calculating Power, How Does a Researcher Know What Estimate