This article by Carmen R. Wilson VanVoorhis and Betsy L. Morgan from the University of Wisconsin-La Crosse discusses the concept of power in statistical analysis and its relationship to Type I and Type II errors. The authors emphasize the importance of considering power during the design phase of research to ensure that studies are adequately powered to detect meaningful differences or associations. They provide guidelines for increasing power, including increasing sample size and effect size, and offer "rules of thumb" for determining the appropriate number of participants for common statistical procedures such as t-tests, ANOVA, regression, chi-square, and factor analysis. The article also highlights the practical considerations researchers face, such as time, resource constraints, and the need to balance sample size with the ability to conduct the study. The authors conclude by emphasizing the importance of reporting sample size and power analysis in research protocols and manuscripts, as recommended by the Task Force on Statistical Inference and the American Psychological Association's guidelines.This article by Carmen R. Wilson VanVoorhis and Betsy L. Morgan from the University of Wisconsin-La Crosse discusses the concept of power in statistical analysis and its relationship to Type I and Type II errors. The authors emphasize the importance of considering power during the design phase of research to ensure that studies are adequately powered to detect meaningful differences or associations. They provide guidelines for increasing power, including increasing sample size and effect size, and offer "rules of thumb" for determining the appropriate number of participants for common statistical procedures such as t-tests, ANOVA, regression, chi-square, and factor analysis. The article also highlights the practical considerations researchers face, such as time, resource constraints, and the need to balance sample size with the ability to conduct the study. The authors conclude by emphasizing the importance of reporting sample size and power analysis in research protocols and manuscripts, as recommended by the Task Force on Statistical Inference and the American Psychological Association's guidelines.